Evaluation of the antifungal effect of plant extracts on oral Candidaspp. - a critical methodological analysis of the last decade

INTRODUCTION

In 2022, the World Health Organization published a report encouraging researchers to focus on Candida spp. to strengthen the global response to fungal oral infections and antifungal resistance. In the context of innovative research, it seems pertinent to investigate the antifungal potential of natural extracts of plants and the methodology involved in the recent reports. The aim of this systematic review is to identify the current state of in vitro research on the evaluation of the ability of plant extracts to inhibit Candida spp.

MATERIAL AND METHODS

A bibliographic search has been developed to on a 10-year period to identify which plant extracts have an antifungal effect on the Candida spp. found in the oral cavity.

RESULTS

A total of 20 papers were reviewed and fulfilled all the selection criteria and were included in the full data analysis.

DISCUSSION

Plants have been tested in a wide range of states - whole extracts, extraction of particular components such as flavonoids or polyphenols, or even using the plant to synthesize nanoparticles. Of forty-five plants tested, five of them did not show any effect against Candida spp., which weren't part of the same family. There is a wide range of plant that exhibit antifungal proprieties.

CONCLUSION

Many plants have been tested in a wide range of states - whole extracts, extraction of components such as flavonoids or polyphenols, or even using the plant to synthetize nanoparticles. The combination of plants, the addition of plants to a traditional antifungal and the interference with adhesion provided by some plants seem to be promising strategies. Nonetheless, on contrary to drugs, there is a critical lack of standardization on methodologies and protocols, which makes it difficult to compare data and, consequently, to conclude, beyond doubts, about the most promising plants to fight Candida spp. oral infections.

Phytochemical characterization of the Ziziphus joazeiro Mart. metabolites by UPLC-QTOF and antifungal activity evaluation

The aim of this study was to evaluate the antifungal and modulatory potential of the Ziziphus joazeiro bark and leaf extracts, both in isolation and in association with fluconazole, against resistant species from the Candida genus. Antifungal assays were used to determine the half maximal inhibitory concentration (IC50) of the extract in isolation and in combination with fluconazole using the broth microdilution method and spectrophotometric readings, followed by verification of the minimum fungicidal concentration by solid medium subculture. According to the cell viability curve, both extracts inhibited fungal growth in a concentration dependent manner, in addition to showing inhibitory concentrations similar to fluconazole. However, the extracts behaved in a fungistatic manner with minimum inhibitory concentration > 8.19 mg/mL and IC50 values ranging from 0.450 mg/mL to 9 mg/mL. The minimum inhibitory concentration for both extracts decreased when in combination with fluconazole, with the AEL standing out against Candida albicans URM 4387, displaying an IC50 equal to that of fluconazole (0.002 mg/mL). Nevertheless, fluconazole antagonism was observed against the tested strains. Overall, the evaluation of both extracts against Candida spp. presented inhibitory concentration values greater than fluconazole. Moreover, despite these being chemically complex crude extracts, they did demonstrate antifungal effects and properties that concur with their ethno-biological aspect.

Phytochemical characterization of the Ziziphus joazeiro Mart. metabolites by UPLC-QTOF and antifungal activity evaluation

The aim of this study was to evaluate the antifungal and modulatory potential of the Ziziphus joazeiro bark and leaf extracts, both in isolation and in association with fluconazole, against resistant species from the Candida genus. Antifungal assays were used to determine the half maximal inhibitory concentration (IC50) of the extract in isolation and in combination with fluconazole using the broth microdilution method and spectrophotometric readings, followed by verification of the minimum fungicidal concentration by solid medium subculture. According to the cell viability curve, both extracts inhibited fungal growth in a concentration dependent manner, in addition to showing inhibitory concentrations similar to fluconazole. However, the extracts behaved in a fungistatic manner with minimum inhibitory concentration > 8.19 mg/mL and IC50 values ranging from 0.450 mg/mL to 9 mg/mL. The minimum inhibitory concentration for both extracts decreased when in combination with fluconazole, with the AEL standing out against Candida albicans URM 4387, displaying an IC50 equal to that of fluconazole (0.002 mg/mL). Nevertheless, fluconazole antagonism was observed against the tested strains. Overall, the evaluation of both extracts against Candida spp. presented inhibitory concentration values greater than fluconazole. Moreover, despite these being chemically complex crude extracts, they did demonstrate antifungal effects and properties that concur with their ethno-biological aspect.

Serine protease inhibition and modulatory-antibiotic activity of the proteic extract and fractions from Amburana cearensis

This study investigated the inhibitory activity of serine protease, as well as antibacterial and antibiotic modifying activities of the crude extract and fractions of A. cearensis seeds. Microdilution assay was used to evaluate the antibacterial activity and the antibiotic resistance-modulating effects of samples against multiresistant bacteria Staphylococcus aureus (SA10) and Escherichia coli (EC06). In the inhibition test for serine protease, all the samples showed inhibition of enzymatic activity. Crude extract and fractions of A. cearensis seeds showed a Minimum Inhibitory Concentration ≥1024 μg/mL for all microorganisms tested. However, the samples acted as resistance modifying agent, presenting synergism when associated with gentamicin, norfloxacin and penicillin. The present study provides data indicating a possible use of the seeds extract of A. cearensis in association with antibiotics in the fight against bacterial infections.

Cholecalciferol, Ergosterol, and Cholesterol Enhance the Antibiotic Activity of Drugs

Abstract. Background: This is the first report demonstrating the antibiotic-modifying activity of cholecalciferol. Aim: In this study, cholecalciferol was evaluated against multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Methods: The antibacterial and modulatory effects of cholecalciferol, ergosterol, and cholesterol (8–512 μg/mL) were evaluated by microdilution assay against multiresistant bacterial strains. Results: Cholecalciferol, when combined with aminoglycosides, was more effective against P. aeruginosa, reducing the concentration of amikacin and gentamicin necessary to inhibit bacterial growth from 156.25 to 39.06 μg/mL and from 39.06 to 9.76 μg/mL, respectively. It is possible that cholecalciferol, due to its lipid-soluble nature, had a lipophilic interaction with the cell membrane, enhancing antibiotic uptake. Cholesterol and ergosterol were used to see if the mechanism of action of cholecalciferol was similar to that of these lipid compounds. Ergosterol and cholesterol increased aminoglycoside activity, where the effect was greater with higher subinhibitory concentration of sterol. Conclusions: There is no reported study on the use of cholesterol and ergosterol as modulators of antibiotics or any other drug, making this the first study in this area highlighting the interaction between cholesterol, ergosterol, and cholecalciferol with regard to modifying aminoglycoside activity.

Action of cholecalciferol and alpha-tocopherol on Staphylococcus aureus efflux pumps

Alpha-tocopherol is one the most abundant and biologically active isoforms of vitamin E. This compound is a potent antioxidant and one of most studied isoforms of vitamin E. Vitamin D3 (cholecalciferol) is an important nutrient for calcium homeostasis and bone health, that has also been recognized as a potent modulator of the immune response. Methicillin-resistant Staphylococcus aureus (MRSA) is the most important causative agent of both nosocomial and community-acquired infections. The aim of this study was to evaluate the inhibitory effect of alpha-tocopherol and cholecalciferol on both S. aureus and multidrug resistant S. aureus efflux pumps. The RN4220 strain has the plasmid pUL5054 that is the carrier of gene that encodes the macrolide resistance protein (an efflux pump) MsrA; the IS-58 strain possesses the TetK tetracycline efflux protein in its genome and the 1199B strain resists to hydrophilic fluoroquinolones via a NorA-mediated mechanism. The antibacterial activity was evaluated by determining the Minimal Inhibitory Concentration (MIC) and a possible inhibition of efflux pumps was associated to a reduction of the MIC. In this work we observed that in the presence of the treatments there was a decrease in the MIC for the RN4220 and IS-58 strains, suggesting that the substances presented an inhibitory effect on the efflux pumps of these strains. Significant efforts have been done to identify efflux pump inhibitors (EPIs) from natural sources and, therefore, the antibacterial properties of cholecalciferol and alpha-tocopherol might be attributed to a direct effect on the bacterial cell depending on their amphipathic structure.

The effect of thermal treatment of whole soybean flour on the conversion of isoflavones and inactivation of trypsin inhibitors

The aim of this paper was to evaluate the effect of the thermal treatment of whole soybean flour (WSF) on the conversion of isoflavones and the inactivation of trypsin inhibitors. Soybeans were ground and whole soybean flour was obtained and subjected to heat treatment in an oven for 10, 15 and 20min at 100, 150 and 200°C according to a 3(2) experimental design. The response functions were taken to be the contents of different isoflavone forms and the residual activity of trypsin inhibitors. The thermal treatment in the oven altered the content and profile of the different isoflavones forms. At 200°C for 20min, there was a higher conversion of malonylglycosides to acetylglycosides, β-glycosides and aglycones and a significant reduction in the activity of trypsin inhibitors. Mathematical models were established to estimate the process parameters in obtaining the WSF with isoflavone conversions and reductions in trypsin inhibitor activity.

[Tibiotalocalcaneal arthrodesis using a humeral locking plate]

OBJECTIVE

To describe the results of tibiotalocalcáneal arthrodesis (TTC) using a humeral locking plate.

METHODS AND MATERIALS

A retrospective, observational study was conducted between January 2007 and December 2013 in the Hospital Militar Central de Bogotá. The study included patients with symptomatic osteoarthritis diagnosed clinically and radiologically, and who underwent TTC arthrodesis using a humeral locking plate with a minimum follow up of 6 months.

RESULTS

The total number patients was 35, of whom 7 (20%) were women and 28 (80%) men, with a mean age 36.3 years (19.77).

AETIOLOGY

74% with post-traumatic arthritis, most of them secondary to gunshot wounds and fragmentation weapons, and neuropathic in 20%. An autogenous graft was used in 13 cases, and 14 cases using both, with a mean consolidation time of 4.37 months. Complications include, delayed union in 3 cases, and surgical site infection in 4. The postoperative functionality (AOFAS) mean was 66.7/100 points, with a score of 2.35 on a visual analogue pain scale.

CONCLUSION

TTC arthrodesis using a humeral locking plate is a suitable option for fixing this type of arthrodesis, with a low rate of complications, and postoperative results that revealed satisfactory improvement in pain and consolidation.

Menadione (vitamin K) enhances the antibiotic activity of drugs by cell membrane permeabilization mechanism

Menadione, vitamin K3, belongs to the class of lipid-soluble vitamins and lipophilic substances as menadione cause disturbances in the bacterial membrane, resulting in damage to the fundamental elements for the integrity of the membrane, thus allowing increased permeability. Accordingly, the aim of this study was to evaluate in vitro the antibiotic-modifying activity of menadione in multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, with a gradual increase in its subinhibitory concentration. In addition, menadione was compared with cholesterol and ergosterol for similarity in mechanism of drug modulatory action. Antibiotic-modifying activity and antibacterial effect were determined by the broth microdilution assay. Menadione, cholesterol and ergosterol showed modulatory activity at clinically relevant concentrations, characterizing them as modifiers of bacterial drug resistance, since they lowered the MIC of the antibiotics tested. This is the first report of the antibacterial activity of menadione and its potentiation of aminoglycosides against multiresistant bacteria.

Shifted convolution and the Titchmarsh divisor problem over 𝔽q[t]

In this paper, we solve a function field analogue of classical problems in analytic number theory, concerning the autocorrelations of divisor functions, in the limit of a large finite field.

Enhancement of the antibiotic activity of aminoglycosides by alpha-tocopherol and other cholesterol derivates

Alpha-tocopherol, one of the most abundant isoforms of vitamin E, is a biologically active liposoluble vitamin and potent antioxidant. It occurs naturally in foods of plant and animal origin. Because of its lipophilic character, it can cause perturbations in the bacterial cell membrane, resulting in damage to components essential for the integrity of the membrane, thereby allowing an increase in permeability. This is the first report of the modulatory effect of alpha-tocopherol in multiresistant bacteria. We evaluated alpha-tocopherol against multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, and determined if there was any similarity with the mechanism of modulatory action of cholesterol and ergosterol. When combined with aminoglycosides in a microdilution broth assay, alpha-tocopherol possibly acted through a lipophilic action on the cell envelope, modulating more effectively P. aeruginosa and E. coli, when compared with S. aureus.

Drug-delivery systems of green tea catechins for improved stability and bioavailability

Numerous studies in humans, animal models and cell lines have suggested the potential benefits from the consumption of green tea polyphenols, including prevention of cancer and heart diseases. However these potential effects have been strongly limited by green tea catechins low bioavailability, which hinders the development of therapeutic applications. In this review formulations that are being proposed for delivery of green tea catechins are discussed. New delivery systems are presented as valid alternatives to overcome the limitations such as green tea catechins poor stability or intestinal absorption.

Chemical composition and evaluation of modulatory of the antibiotic activity from extract and essential oil of Myracrodruon urundeuva

CONTEXT

The combination of antibiotics with natural products has demonstrated promising synergistic effects in several therapeutic studies.

OBJECTIVE

The aim of this study was to determine the effect of a combination of an ethanol extract of Myracrodruon urundeuva Fr. All. (Anacardiaceae) (aroeira plant) and its essential oil with six antimicrobial drugs against multiresistant strains of Staphylococcus aureus and Escherichia coli from clinical isolates.

MATERIALS AND METHODS

After identification of the chemical components by GC-MS, the antibacterial activity of the natural products and antibiotics was assessed by determining the minimal inhibitory concentration (MIC) using the microdilution method and concentrations ranging 8-512 μg/mL and 0.0012-2.5 mg/mL, respectively. Assays were performed to test for a possible synergistic action between the plant products and the antimicrobials, using the extract and the oil at a sub-inhibitory concentration (128 μg/mL) and antibiotic at concentrations varying between 8 and 512 μg/mL.

RESULTS

The GC-MS analysis identified the main compound as δ-carene (80.41%). The MIC of the natural products was >1024 μg/mL, except against S. aureus ATCC25923. Only the combinations of the natural products with gentamicin, amikacin and clindamycin were effective against S. aureus 358, enhancing the antibiotic activity by reducing the MIC.

CONCLUSIONS

The extract from aroeira showed a higher antibacterial activity and the oil was more effective in potentiating the activity of conventional antibiotics.

Phenolic compounds and interaction between aminoglycosides and natural products of Lygodium venustum SW against multiresistant bacteria

BACKGROUND

The aim of this work was to evaluate the interactions between aminoglycosides and the ethyl-acetate fraction of the fern Lygodium venustum SW (EAFLV) METHODS: The ethyl-acetate fraction was obtained from the ethanol extract of L. venustum and was assayed via the checkerboard method associated with aminoglycosides against two bacterial strains multiresistant to antibiotics.

RESULTS

The antibiotic activity of all drugs, when associated with the ethyl-acetate fraction, was enhanced in an additive manner, except for the association between EAFLV and amikacin, which showed a synergistic interaction against the Escherichia coli strain.

CONCLUSIONS

The results indicated that L. venustum can be a source of secondary metabolites to be used in association with antibiotics like aminoglycosides in antibiotic chemotherapy against resistant bacteria.

Production of 1,3-Propanediol by Clostridium butyricum VPI 3266 in continuous cultures with high yield and productivity

The effects of dilution rate and substrate feed concentration on continuous glycerol fermentation by Clostridium butyricum VPI 3266, a natural 1,3-propanediol producer, were evaluated in this work. A high and constant 1,3-propanediol yield (around 0.65 mol/mol), close to the theoretical value, was obtained irrespective of substrate feed concentration or dilution rate. Improvement of 1,3-propanediol volumetric productivity was achieved by increasing the dilution rate, at a fixed feed substrate concentration of 30, 60 or 70 g l(-1). Higher 1,3-propanediol final concentrations and volumetric productivities were also obtained when glycerol feed concentration was increased from 30 to 60 g l(-1), at D=0.05-0.3 h(-1), and from 60-70 g l(-1), at D=0.05 and 0.1 h(-1).30 g l(-1) of 1,3-propanediol and the highest reported value of productivity, 10.3 g l(-1) h(-1), was achieved at D=0.30 h(-1) and 60 g l(-1) of feed glycerol. A switch to an acetate/butyrate ratio higher than one was observed for 60 g l(-1) of feed glycerol and a dilution rate higher than 0.10 h(-1); moreover, at D=0.30 h(-1) 3-hydroxypropionaldehyde accumulation was observed for the first time in the fermentation broth of C. butyricum.

Production of 1,3-propanediol by Clostridium butyricum VPI 3266 using a synthetic medium and raw glycerol

Growth inhibition of Clostridium butyricum VPI 3266 by raw glycerol, obtained from the biodiesel production process, was evaluated. C. butyricum presents the same tolerance to raw and to commercial glycerol, when both are of similar grade, i.e. above 87% (w/v). A 39% increase of growth inhibition was observed in the presence of 100 g l(-1) of a lower grade raw glycerol (65% w/v). Furthermore, 1,3-propanediol production from two raw glycerol types (65% w/v and 92% w/v), without any prior purification, was observed in batch and continuous cultures, on a synthetic medium. No significant differences were found in C. butyricum fermentation patterns on raw and commercial glycerol as the sole carbon source. In every case, 1,3-propanediol yield was around 0.60 mol/mol glycerol consumed.

Importance of intraoperative transesophageal echocardiography during coronary artery surgery without cardiopulmonary bypass

The goal of this study was to assess left ventricular segmental wall motion (SWM) abnormalities during coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB), and its impact on the immediate postoperative outcome. Transesophageal echocardiography was used intraoperatively in 27 patients (mean age 57 years) who had CABG without CPB. Images obtained with a 5-MHz biplane transesophageal echocardiographic probe in the transgastric and transesophageal planes were recorded before, during, and after 48 coronary artery clampings for saphenous vein or internal mammary artery anastomosis. Transthoracic echocardiography was performed 1 day before surgery and on the seventh postoperative day. During the 48 coronary artery clampings, 31 (64%) new SWM abnormalities were found. At the time of chest closure, complete recovery occurred in 16 (50%) segments, partial recovery in 10 (33%), and no recovery in 5 (17%). On the seventh postoperative day the new SWM abnormalities persisted in all 5 segments without recovery at the end of the surgery and in 2 of 10 (20%)segments with partial recovery (group 1). Group 1 had higher variation on the echocardiographic point score index between the beginning and end of surgery, higher enzymatic levels, more ST-T changes on the electrocardiogram, and more clinical problems than group 2 (patients without new SWM abnormalities on the seventh postoperative day) (P < .05). We concluded that new SWM abnormalities of the left ventricle occur during CABG without CPB as assessed by intraoperative transesophageal echocardiography. Persistence of these abnormalities at the end of surgery may be a predictor of SWM dysfunction and clinical problems in the immediate postoperative period.

On the incidence of the biceps brachii third head in Brazilian white and blacks

The incidence of a third head of the biceps brachii muscle has been reported in several articles, and there is a general idea that it is a race-dependent variation. The aim of this investigation was to study the biceps brachii muscle with regard to the incidence of its third head in a mixed white and black Brazilian population. A total of 200 upper arms from adult white and black cadavers (100 whites and 100 blacks) fixed in a 10% formol solution were examined and compared. It was observed that for white subjects the incidence of the third head was 20% against 9% for the black subjects: a statistically significant difference. We suggest that other factors, in addition to racial ones, might play a part in determining the incidence of the biceps brachii third head in a population.

Mitral valve replacement with glutaraldehyde preserved aortic allografts

OBJECTIVE

To present long-term results after mitral valve replacement with stent mounted glutaraldehyde preserved aortic allografts in patients older than 15 years. The clinical support for this study was to combine the glutaraldehyde technique of biological tissue preservation with the advantages of allografts when compared to xenografts. This was demonstrated in previous studies using other methods of tissue processing.

METHODS

Between September 1984 and November 1994, 70 patients aged 16-77 years (mean 35.4 years) underwent mitral valve replacement with this preserved and mounted allograft. Of these, 40 patients (57.2%) were aged 16-35 years and 15 (21.4%) were 20 years old or younger; 46 (65.7%) were females and 24 (34.3%) males. Single mitral valve replacement was performed in 60 patients and 10 were also subjected to other combined cardiac procedures. Human aortic valves were obtained during routine autopsy, processed in glutaraldehyde and mounted into flexible stents, using the same technique as that used for porcine bioprostheses.

RESULTS

Hospital mortality was 1.4%. Total follow-up was 543.1 patient-years, corresponding to a mean follow-up of 7.9 years per patient. Echocardiography demonstrated a hemodynamic performance similar to porcine bioprostheses. Late mortality was 0.7 +/- 0.6% per patient-year and the causes were congestive heart failure in 2, prosthetic endocarditis in 1 and acute myocardial infarction in 1. The 12-year actuarial survival was 92.4 +/- 3.2%. The incidence of late complications was 5.2 +/- 1.2% per patient-year, including congestive heart failure, prosthetic endocarditis, periprosthetic leak, thromboembolic episodes, recurrence of rheumatic disease, coronary artery disease and allograft failure. Complications related to heart disease represented 2.8 +/- 0.6% and allobioprosthesis-related 2.4 +/- 0.5% per patient-year. The 12-year actuarial freedom from primary valve failure was 81.0 +/- 15.0%. The incidence of reoperations was 1.5 +/- 0.8% per patient-year and the main indication was prosthetic endocarditis. Other causes were periprosthetic leak, aortic insufficiency in the native aortic valve and allobioprosthesis dysfunction. Functional results demonstrated a significant improvement in patients clinical condition.

CONCLUSION

This 12-year follow-up shows a very low incidence of primary allograft failure for patients older than 15 years undergoing mitral valve replacement, and much superior than our results with porcine bioprosthesis in the same age group. This supports our assumption that this investigational valve represents a new advance in cardiac valve surgery.

[Partial atrioventricular septal defect associated with right atrioventricular valve Ebstein's disease]

The association of Ebstein's disease and atrioventricular septal defect is extremely rare with only 13 cases described in the literature and none in our country. We described a 15 year-old girl with echo and angiographic diagnosis confirmed by surgery. The non-identification of one of the lesions could impair planning and surgical results.

Surgical treatment of acute type B aortic dissection using an endoprosthesis (elephant trunk)

BACKGROUND

The surgical treatment of acute complicated type B aortic dissection continues to be a challenge and is still associated with high morbidity and mortality rates.

METHODS

Seventy consecutive patients with an acute type B aortic dissection underwent an elephant trunk procedure through a median sternotomy during deep hypothermic circulatory arrest. An endoprosthesis that was 22 to 24 mm in diameter was inserted through an incision in the arch and held in place with only proximal sutures.

RESULTS

The mean arrest time was 31.4 +/- 8.7 minutes, and it was possible to adequately position the endoluminal graft in every patient. The procedure was done in association with other procedures in 13 patients. There were six in-hospital deaths not related to the endoprosthesis, and four late deaths. Late reoperation was necessary in 6 patients to manage leakage at the proximal suture line.

CONCLUSIONS

The insertion of an endoprosthesis through the arch for the management of a complicated acute type B dissection has several advantages over the conventional thoracotomy approach. The hospital mortality rate in this series of 70 patients was 20%, and the actuarial 5-year survival rate was 62.5%. We consider the elephant trunk procedure the treatment of choice in patients with type B acute dissections, regardless of whether the dissection is complicated or not.

Transaortic approach has a role in the surgical treatment of ventricular septal defects

A transaortic approach was used for surgical closure of ventricular septal defects (VSDs), sometimes as first choice and otherwise as an alternative approach. This paper presents the experience in a group of 124 patients who underwent VSD closure by a transaortic approach in an 18-year-period, between 1974 and 1992. Patients were divided in three groups: (I) Isolated VSD, 89 patients (mean age 7.6 years); (II) VSD associated with other malformations, 27 patients (mean age 10.8 years); and (III) recurrent VSD, eight patients (mean age 15.6 years). Two deaths occurred in the postoperative period (2/124), one after closure of VSD in a patient with severe pulmonary hypertension; another death was observed after transaortic closure of the VSD as part of the repair of a complex heart malformation. There were no instances of new right bundle branch block (RBBB) in the group operated on for isolated VSDs. Three cases of left bundle branch block (LBBB) (3.4%) occurred in the isolated VSD group. There were no cases of complete aortic valve (AV) block in the whole series and no instances of AV dysfunction. The transaortic approach is an alternative for the surgical treatment of ventricular septal defects. The ease of exposure and closure of defects suggest this technique to be a particularly attractive approach in the treatment of small to moderate-sized VSDs and also in recurrent VSDs.

[Myocardial revascularization without extracorporeal circulation. Surgical results in 1090 patients]

PURPOSE

To report our experience of 12 years of myocardial revascularization without cardiopulmonary bypass (CPB) and to discuss its expanding surgical indications.

METHODS

This technique was employed in 1090 patients, between September/81 and April/93, corresponding to 17.4% of all revascularized patients. Regarding gender, male patients were the majority (73.7%) and ages ranged from 28 to 86 year-old (mean 57). Chronic coronary insufficiency was the main indication (69.4%) and 18.9% of our global experience were operated on during acute ischemia. The average number of grafts per patient was 1.6 and internal mammary artery was utilized in 60.1% of patients. Left anterior descending coronary artery and right coronary artery were the coronary arteries most often treated.

RESULTS

Our hospital mortality rate was 2.5% (28/1090) although it was 7% for patients over 70 years. The most common cause of death was cardiogenic shock after failed angioplasty. Postoperative complications included AMI in 4.8%, arrhythmias in 5.5% and pulmonary in 3.2%. Mean of any type of blood derivate utilization was 0.28 units/patients.

CONCLUSION

Myocardial revascularization without CPB is a valid alternative in a selected cohort of patients and it is performed with low morbidity and mortality. Nowadays it represents an excellent tactical option for high-risk patients and in failed angioplasties.

[Late development of congestive heart failure in interventricular communication caused by penetrating wound, with pulmonary hypertension resolution after surgical correction]

Male, 33 years-old, with onset of heart failure and edema; he used to be completely asymptomatic but mentioned he underwent previously a pleural drainage, after a hemothorax provoked by a stab wound. His physical examination confirmed he was in heart failure and showed a harsh holosystolic murmur between mitral and tricuspid areas. Cardiac catheterization demonstrated a large apical ventricular septal defect (VSD) and systemic pulmonary arterial pressures. With oxygen there was an increase in the left to right shunt and normal pulmonary vascular resistance. The clinical diagnosis was that of a traumatic VSD provoking pulmonary hypertension although a congenital etiology could not be completely ruled out. At surgery there was a sharp cut at the pericardium and an apical epicardial lesion; the VSD was patch sutured and the patient did well with control of his heart failure. A control hemodynamic study performed within the first postoperative month showed no residual shunt and complete normalization of the pulmonary pressures and resistance.

[Hemodynamic study with Swan-Ganz catheterization, concomitant to endomyocardial biopsy in heart transplantation patients. Importance in the early diagnosis of rejection]

PURPOSE

To evaluate the role of hemodynamic parameters in the diagnosis of acute rejection who underwent orthotopic cardiac transplantation.

METHODS

A protocol was carried out in 19 patients who underwent heart transplantation and in whom Swan-Ganz hemodynamics was performed immediately prior to routine endomyocardial biopsy in the first few months postoperatively. The results of 28 biopsies were divided in group I--severe rejection who needed pulse-therapy (n = 10) and group II--No or mild/moderate rejection who did not need any pulse (n = 18). Hemodynamic parameters were compared between both groups.

RESULTS

There were significant differences among hemodynamic parameters in groups I and II. Group I had higher mean right atrial pressures (13.0 x 7.3 mmHg), mean pulmonary pressure (26.3 x 20.4 mmHg), mean wedge pressure (14.4 x 10.9 mmHg) and lower cardiac index (2.57 x 3.10 l/min/m2).

CONCLUSION

In a routine situation, hemodynamic measurements, as obtained with Swan-Ganz catheter, simultaneously with endomyocardial biopsies, show significant alterations in transplanted patients who develop acute rejection. This information, obtained earlier than the biopsy results, could shorten the time to initiate pulse-therapy in patients with severe rejection.

[Early and late results of myocardial revascularization after coronary thrombolysis with intravenous streptokinase in the treatment of acute myocardial infarction]

PURPOSE

To study the early and late results of patients treated initially intravenous streptokinase and then with coronary artery bypass surgery.

METHODS

One hundred and twenty one patients with acute myocardial infarction less than 6 hours duration were treated initially with intravenous streptokinase, and 1-38 days after (median 8.80 days) coronary artery bypass was undertaken. Ninety six patients were operated with extracorporeal circulation and 25 without it.

RESULTS

Overall operative mortality was 3.30% (4/121). Reoperations due to bleeding was necessary in 3.30% (4/121). Late mortality was 5.40% with survival probability of 94.60% after 36 months and 92.30% after 70 months. Late morbidity events in terms of angina and cardiac insufficiency demonstrated that 7 patients had angina, 4 cardiac insufficiency and two angina and cardiac insufficiency; probability to be free from these events was 88.20% after 46 months and 66.40% after 70 months.

CONCLUSION

Coronary artery bypass surgery after intravenous streptokinase can be undertaken with security and excellent early and late results.

[Systemic-pulmonary shunts in congenital heart diseases with decreased pulmonary blood flow: critical analysis of the surgical techniques and immediate results]

PURPOSE

To evaluate immediate postoperative results in children with congenital heart disease and decreased pulmonary blood flow who underwent a systemic to pulmonary shunt.

PATIENTS AND METHODS

Sixty-four patients underwent surgery, 46.8% (30) of them males with ages from 1 day to 17 years old. They were divided in three groups: I--13 pts (20.3%) who underwent classical Blalock-Taussig (BT) shunt; II--46 pts (71.8%) who underwent modified BT shunts, 34 of them with polytetrafluoroetylene (PTFE) and 12 of them with umbilical vein shunts; III--5 pts (7.8%) with central anastomosis that were made with three different types of graft; 3 PTFE, umbilical vein and bovine mammary artery in one each. The simultaneous procedures were: section and suture of PDA--2, closure of systemic-pulmonary collaterals--3, pulmonary valvotomy--3, right ventricular outflow patch--3, pulmonary branch stenosis (enlargement)--2.

RESULTS

In group I there were 4 (30.7%) closures, with two immediate reoperation and a total mortality of 30.7%. In group II there were 4 closures (8.6%) and two reoperations with a mortality of 15.2% (7 cases). In group III there was one graft closure and an overall mortality of 80% (4 pts). When analysing deaths due to the shunt itself the mortality rate was respectively 15.3%, 8.6% and 40.0%.

CONCLUSION

Modified BT operation was performed most frequently in our service; it was associated with less closure and mortality than the other types of shunt. It is considered our first alternative for a systemic-pulmonary shunt.

Cardiac valve replacement with glutaraldehyde preserved aortic allografts

From September 1984 to December 1988, 144 patients underwent cardiac valve replacement using glutaraldehyde preserved stent mounted aortic allografts. The mean age was 21.4 years (54.9% were 15 years old or younger). The mitral valve was replaced in 125 patients, the aortic valve in 7, the pulmonary valve in 3, the tricuspid in 1, the mitral and tricuspid in 1, and the aortic and mitral in 7. Hospital mortality was 2.8% (4 patients). Total follow-up was 396.3 patient-years and the mean follow-up was 2.8 years per patient. The 5-year actuarial survival was 73.8% +/- 11.9%. The 4-year actuarial survival for patients aged 15 or younger was 81.4% +/- 7.1%. The overall mortality was 2.8% +/- 0.8%/per patient-year. The incidence of valve-related complications was 4.8% +/- 1.1%/per patient-year, and the calcification rate was 3.0% +/- 0.9%/per patient-year and was the main complication reported in 12 patients, all under the age of 15 years. It occurred 14-47 months after implantation (mean 32.7 months). Five-year actuarial freedom from valve dysfunction due to calcification was 82.6% +/- 5.0% and for patients aged 15 or younger was 69.9% +/- 8.8%. The incidence of reoperation was 3.3% +/- 0.9%/per patient-year. These initial results demonstrate a 5-year actuarial freedom from primary valve failure due to fibrocalcification superior to the results obtained with xenobioprostheses in the paediatric age group.

Myocardial revascularization without extracorporeal circulation. Seven-year experience in 593 cases

The authors present the results of 593 consecutive and non-selected patients who underwent direct myocardial revascularization without extracorporeal circulation in the period September 1981 to December 1988. The results are compared with 3086 patients who underwent conventional bypass surgery over the same period of time. The ages varied from 33 to 80 years (mean = 56) with 40 patients older than 70. The overall mortality in the group without cardiopulmonary bypass (CPB) was 1.7% (10/593) compared with 3.8% for conventional revascularization. Our mortality in the last 3 years has been 0.5% and 0% in the last 203 patients revascularized without CPB. The number of grafts varied from 1 to 5 (average 1.6). The treated arteries were: anterior descending (557), right (282) marginal (5) and circumflex marginal (4). Immediate postoperative complications were fewer and hospital discharge was earlier in the group treated without CPB. The authors conclude that this tactical alternative has the advantages of: lower morbidity and mortality, lower cost and no need for blood transfusion. Drawbacks are the need for greater technical expertise and it seems to be possible in about 19% of all patients who undergo myocardial revascularization.

Serum ferritin and hemochromatosis alleles in chronic hemodialysis patients

There have been some reports on the risk of developing hemosiderosis in hemodialysis patients when heavily transfused and simultaneously possessing hemochromatosis alleles (HA). We evaluated 99 patients on chronic hemodialysis estimating their serum ferritin (SF) levels, transfusion rate, and prevalence of HLA A3, B7 and B14 alleles, which are considered to be more frequent in idiopathic hemochromatosis. We analyzed the patients as a whole group and also separately as low or high transfusion groups. There was no correlation between the number of HA and the mean SF levels. The presence of HA is not a risk factor for the development of hemosiderosis when excessive transfusions and parenteral iron administration are avoided.

Modified Blalock-Taussig shunt with an umbilical vein graft

We describe a modification of the Blalock Taussig anastomosis, with the interposition of a glutaraldehyde-tanned umbilical vein graft between the subclavian and pulmonary arteries. This operation was performed in 64 children: 11 were less than 1 month of age (17.2%), and 23 were between 1 and 6 months of age (34.9%). Hospital deaths occurred in six patients-all less than 6 months of age (9.4%). There was no instance of shunt occlusion noted. The clinical course was uneventful among survivors, except for one patient who died of endocarditis in the late postoperative follow-up. The shunt procedure may be performed very rapidly, with minimal dissection, allowing the use of a graft larger than the diameter of the subclavian artery. This modification of the Blalock Taussig operation compares favorably with our previous experience with other shunt procedures and may be considered a valuable alternative in the palliative surgical treatment of several malformations with severe pulmonary oligemia.

Direct myocardial revascularization without extracorporeal circulation: technique and initial results

In a 10-month period, 68 patients underwent saphenous vein bypass revascularization without extracorporeal circulation. Distal sutures were performed with interruption of coronary flow without any devices for perfusion of the coronary artery; the proximal sutures were completed with tangential clamping of the aorta. Most frequently, the anterior descending and the distal right coronary arteries were revascularized; of 225 patients who underwent bypass surgery, this technique was possible in 68 cases (30.2%). The 30-day hospital mortality was 1.5%, and perioperative myocardial infarction, as determined by daily electrocardiograms (ECGs) and creatine phosphokinase isoenzyme (CKMB), occurred in two patients. Control hemodynamic studies were performed in 22 of the 68 patients (32.4%) with a patency rate of 84.2% in the grafts restudied.

Direct myocardial revascularization without cardiopulmonary bypass

The authors present their experience with 160 patients who underwent coronary artery saphenous vein bypass revascularization without cardiopulmonary bypass. The distal sutures were performed with interruption of the coronary flow without any devices for perfusion of the coronary artery: the proximal sutures were made with tangential clamping of the aorta. Vessels most frequently revascularized were the anterior descending and the distal right coronary artery. Out of 597 patients who underwent bypass surgery in this period, this technique could be employed in 160 cases (26.8%). Hospital mortality was 3.1% (5/160) and perioperative myocardial infarction as determined by daily EKGs and CKMB occurred in 4 patients (2.5%). Control hemodynamic studies were performed in 41 of the 160 patients (25.6%) with a patency rate of 83.9% in the 62 grafts restudied. We conclude that direct myocardial revascularization can be performed safely without major difficulties and with efficient anastomoses. The main advantages of the technique are that it does not require the use of extracorporeal circulation and, consequently, the use of any blood, as well as its low cost due to shorter hospitalization periods.

Surgical treatment of endomyocardial fibrosis

Thirty patients with endomyocardial fibrosis were submitted to endocardial decortication and atrioventricular valve replacement between December, 1977, and October, 1981. There were 26 female and four male patients, ranging in age from 14 to 48 years (mean 32). Thirteen patients had biventricular disease, 14 had the right-sided form, and three had endomyocardial fibrosis confined to the left ventricle. All were in Functional Class III or IV (New York Heart Association classification). The hospital mortality was 20% (six cases). Among the survivors (mean follow-up 13 months), 23 of 24 were improved clinically. Postoperative hemodynamic and angiographic studies were performed in 15 patients. Two (6.6%) have definitive atrioventricular heart block. There were five (16.6%) late deaths. Operation for endomyocardial fibrosis should be considered a palliative procedure. Possible limitations include the need for a valve prosthesis, cardiac conduction disturbances secondary to endocardiectomy of the right ventricle, and the possibility of recurrence of the endocardial fibrosis. However, at present, operation seems to be the treatment of choice for this condition because (1) endomyocardial fibrosis is characterized by a grave prognosis and medical therapy is ineffective; (2) endomyocardial fibrosis is a disease in which only the heart is affected, lesions in other organs being the result of passive congestion; (3) systolic performance of the heart is usually only slightly depressed; and (4) the surgical procedure is easily performed, so that the mortality is acceptable.