ChatGPT-3.5 System Usability Scale early assessment among Healthcare Workers: Horizons of adoption in medical practice

Artificial intelligence (AI) chatbots, such as ChatGPT, have widely invaded all domains of human life. They have the potential to transform healthcare future. However, their effective implementation hinges on healthcare workers' (HCWs) adoption and perceptions. This study aimed to evaluate HCWs usability of ChatGPT three months post-launch in Saudi Arabia using the System Usability Scale (SUS). A total of 194 HCWs participated in the survey. Forty-seven percent were satisfied with their usage, 57 % expressed moderate to high trust in its ability to generate medical decisions. 58 % expected ChatGPT would improve patients' outcomes, even though 84 % were optimistic of its potential to improve the future of healthcare practice. They expressed possible concerns like recommending harmful medical decisions and medicolegal implications. The overall mean SUS score was 64.52, equivalent to 50 % percentile rank, indicating high marginal acceptability of the system. The strongest positive predictors of high SUS scores were participants' belief in AI chatbot's benefits in medical research, self-rated familiarity with ChatGPT and self-rated computer skills proficiency. Participants' learnability and ease of use score correlated positively but weakly. On the other hand, medical students and interns had significantly high learnability scores compared to others, while ease of use scores correlated very strongly with participants' perception of positive impact of ChatGPT on the future of healthcare practice. Our findings highlight the HCWs' perceived marginal acceptance of ChatGPT at the current stage and their optimism of its potential in supporting them in future practice, especially in the research domain, in addition to humble ambition of its potential to improve patients' outcomes particularly in regard of medical decisions. On the other end, it underscores the need for ongoing efforts to build trust and address ethical and legal concerns of AI implications in healthcare. The study contributes to the growing body of literature on AI chatbots in healthcare, especially addressing its future improvement strategies and provides insights for policymakers and healthcare providers about the potential benefits and challenges of implementing them in their practice.

Activation of RMTg projections to the VTA reverse cocaine-induced molecular adaptation in the reward system

The rostromedial tegmental nucleus (RMTg) plays a crucial role in regulating reward-related behavior by exerting inhibitory control over the ventral tegmental area (VTA). This modulation of dopamine neuron activity within the VTA is essential for maintaining homeostasis in the reward system. Recently we have shown that activation of RMTg projections to the VTA during the acquisition of cocaine-conditioned place preference (CPP) reduces the rewarding properties of cocaine and decreases VTA dopamine neuron activity. By inhibiting dopamine neurons in the VTA, we hypothesized that RMTg projections hold the potential to restore reward system homeostasis disrupted by repeated cocaine use, and attenuate molecular adaptations in the reward system, including alterations in signaling pathways. Our study demonstrates that enhancing the GABAergic inputs from the RMTg to the VTA can mitigate cocaine-induced molecular changes in key regions, namely the VTA, nucleus accumbens (NAc), and prefrontal cortex (PFC). Specifically, we found that cocaine-induced alteration in the phosphorylation state of ERK (pERK) and GluA1 on serine 845 (S845) and serine 831 (S831), that play a major role in plasticity by controlling the activity and trafficking of AMPA receptors, were significantly reversed following optic stimulation of RMTg afferents to the VTA. These findings highlight the therapeutic potential of targeting the RMTg-VTA circuitry for mitigating cocaine reward. Ultimately, this research may pave the way for novel therapeutic interventions that restore balance in the reward system and alleviate the detrimental effects of cocaine.

Harnessing Machine Learning in Early COVID-19 Detection and Prognosis: A Comprehensive Systematic Review

During the early phase of the COVID-19 pandemic, reverse transcriptase-polymerase chain reaction (RT-PCR) testing faced limitations, prompting the exploration of machine learning (ML) alternatives for diagnosis and prognosis. Providing a comprehensive appraisal of such decision support systems and their use in COVID-19 management can aid the medical community in making informed decisions during the risk assessment of their patients, especially in low-resource settings. Therefore, the objective of this study was to systematically review the studies that predicted the diagnosis of COVID-19 or the severity of the disease using ML. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), we conducted a literature search of MEDLINE (OVID), Scopus, EMBASE, and IEEE Xplore from January 1 to June 31, 2020. The outcomes were COVID-19 diagnosis or prognostic measures such as death, need for mechanical ventilation, admission, and acute respiratory distress syndrome. We included peer-reviewed observational studies, clinical trials, research letters, case series, and reports. We extracted data about the study's country, setting, sample size, data source, dataset, diagnostic or prognostic outcomes, prediction measures, type of ML model, and measures of diagnostic accuracy. Bias was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO), with the number CRD42020197109. The final records included for data extraction were 66. Forty-three (64%) studies used secondary data. The majority of studies were from Chinese authors (30%). Most of the literature (79%) relied on chest imaging for prediction, while the remainder used various laboratory indicators, including hematological, biochemical, and immunological markers. Thirteen studies explored predicting COVID-19 severity, while the rest predicted diagnosis. Seventy percent of the articles used deep learning models, while 30% used traditional ML algorithms. Most studies reported high sensitivity, specificity, and accuracy for the ML models (exceeding 90%). The overall concern about the risk of bias was "unclear" in 56% of the studies. This was mainly due to concerns about selection bias. ML may help identify COVID-19 patients in the early phase of the pandemic, particularly in the context of chest imaging. Although these studies reflect that these ML models exhibit high accuracy, the novelty of these models and the biases in dataset selection make using them as a replacement for the clinicians' cognitive decision-making questionable. Continued research is needed to enhance the robustness and reliability of ML systems in COVID-19 diagnosis and prognosis.

A Machine Learning Model for Predicting the Risk of Readmission in Community-Acquired Pneumonia

Background

Pneumonia is a common respiratory infection that affects all ages, with a higher rate anticipated as age increases. It is a disease that impacts patient health and the economy of the healthcare institution. Therefore, machine learning methods have been used to guide clinical judgment in disease conditions and can recognize patterns based on patient data. This study aims to develop a prediction model for the readmission risk within 30 days of patient discharge after the management of community-acquired pneumonia (CAP).

Methodology

Univariate and multivariate logistic regression were used to identify the statistically significant factors that are associated with the readmission of patients with CAP. Multiple machine learning models were used to predict the readmission of CAP patients within 30 days by conducting a retrospective observational study on patient data. The dataset was obtained from the Hospital Information System of a tertiary healthcare organization across Saudi Arabia. The study included all patients diagnosed with CAP from 2016 until the end of 2018.

Results

The collected data included 8,690 admission records related to CAP for 5,776 patients (2,965 males, 2,811 females). The results of the analysis showed that patient age, heart rate, respiratory rate, medication count, and the number of comorbidities were significantly associated with the odds of being readmitted. All other variables showed no significant effect. We ran four algorithms to create the model on our data. The decision tree gave high accuracy of 83%, while support vector machine (SVM), random forest (RF), and logistic regression provided better accuracy of 90%. However, because the dataset was unbalanced, the precision and recall for readmission were zero for all models except the decision tree with 16% and 18%, respectively. By applying the Synthetic Minority Oversampling TEchnique technique to balance the training dataset, the results did not change significantly; the highest precision achieved was 16% in the SVM model. RF achieved the highest recall with 45%, but without any advantage to this model because the accuracy was reduced to 65%.

Conclusions

Pneumonia is an infectious disease with major health and economic complications. We identified that less than 10% of patients were readmitted for CAP after discharge; in addition, we identified significant predictors. However, our study did not have enough data to develop a proper machine learning prediction model for the risk of readmission.

An animal model for the evaluation of graft thrombosis in the acute phase on carbon-lined PTFE prosthesis

Fortyfive carbon-lined (CL) and 45 standard (ST) 4 mm internal diameter polytetra-fluoroethylene (PTFE) grafts were implanted as aortic interposition in 90 rabbits. A pilot study of 20 animals: 10 CL and 10 ST grafts were used to develop microsurgical techniques, then 60 grafts were placed in 60 New Zealand rabbits with lower morbidity. The two hours graft patency (Doppler and angiographic studies) showed better patency rate in CL group (93% versus 80%). In 10 animals, platelet accumulation was investigated in vivo using gammacamera imaging after injection of autologous platelets labeled with Indium111. In vitro, radioactivity counting of the explanted midgraft sections at 2 hours revealed 6 times greater activity in ST grafts (6.60 ± 1.98 x 103platelets/mm2 versus 0.82 ± 0.25 x 103 platelets/mm2; p<0.05). Light microscopy found platelet and fibrin deposition (PFD) in nearly all ST grafts whereas PFD were found in only 13% of the CL grafts corresponding to those thrombosed (chi2: 61.117, p<0.001). Carbon-lining decreases platelet accumulation on PTFE grafts in the acute phase of a new experimental model.

GelMA-Encapsulated hDPSCs and HUVECs for Dental Pulp Regeneration

Pulpal revascularization is commonly used in the dental clinic to obtain apical closure of immature permanent teeth with thin dentinal walls. Although sometimes successful, stimulating bleeding from the periapical area of the tooth can be challenging and in turn may deleteriously affect tooth root maturation. Our objective here was to define reliable methods to regenerate pulp-like tissues in tooth root segments (RSs). G1 RSs were injected with human dental pulp stem cells (hDPSCs) and human umbilical vein endothelial cells (HUVECs) encapsulated in 5% gelatin methacrylate (GelMA) hydrogel. G2 RSs injected with acellular GelMA alone, and G3 empty RSs were used as controls. White mineral trioxide aggregate was used to seal one end of the tooth root segment, while the other was left open. Samples were cultured in vitro in osteogenic media (OM) for 13 d and then implanted subcutaneously in nude rats for 4 and 8 wk. At least 5 sample replicates were used for each experimental group. Analyses of harvested samples found that robust pulp-like tissues formed in G1, GelMA encapsulated hDPSC/HUVEC-filled RSs, and less cellularized host cell-derived pulp-like tissue was observed in the G2 acellular GelMA and G3 empty RS groups. Of importance, only the G1, hDPSC/HUVEC-encapsulated GelMA constructs formed pulp cells that attached to the inner dentin surface of the RS and infiltrated into the dentin tubules. Immunofluorescent (IF) histochemical analysis showed that GelMA supported hDPSC/HUVEC cell attachment and proliferation and also provided attachment for infiltrating host cells. Human cell-seeded GelMA hydrogels promoted the establishment of well-organized neovasculature formation. In contrast, acellular GelMA and empty RS constructs supported the formation of less organized host-derived vasculature formation. Together, these results identify GelMA hydrogel combined with hDPSC/HUVECs as a promising new clinically relevant pulpal revascularization treatment to regenerate human dental pulp tissues.

Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs

We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

Le phéochromocytome comme cause inhabituelle de choc cardiogénique

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

Liver Transplant Combined With Heart Transplant in Severe Heterozygous Hypercholesterolemia: Report of the First Case and Review of the Literature

Familial hypercholesterolemia (FH) is a dominant inherited disease of low-density lipoprotein (LDL) metabolism caused by mutations of LDL receptors mainly located in the liver. This metabolic disorder is responsible for severe cardiovascular disease, from coronary lesions to chronic heart failure (CHF). Liver transplantation in homozygous FH provides the missing functional LDL receptors and thus partially restores LDL receptor activity to more than 50% of normal. Combined heart and liver transplantation was successfully performed in a homozygous FH patient with end-stage heart failure. Herein we report our experience with a heterozygous male patient with terminal CHF, and review data from the literature on short- and long-term results of such procedures.

Less invasive radial artery harvest

BACKGROUND

Recent studies have sparked a renewed interest in the use of autogenous radial arteries in coronary operations. Some concerns have been found about sequelae of conventional harvesting. A less invasive technique for radial artery harvesting has been proposed by others using endoscopic devices. This technique is time consuming, needs expensive instrumentation and an important learning curve.

METHODS

A new less invasive approach for radial harvesting has been developed with a light assisted retractor under direct vision. A small skin incision, median in the forearm, is followed by dissection of the proper plane of the artery. A subcutaneous tunnel is created around the vessel and all the branches are ligated or clipped. The dissection of the pedicle under the skin is completed with the aid of a modified light assisted retractor, originally designed for the saphenous vein harvesting. The incision is closed after heparin reversal with a small redon as drainage.

RESULTS

A preliminary serie of 15 patients have been operated with this technique. In all patients the radial artery was patent and functional at the postoperative angiography. Morbidity included only a light hematoma at the beginning of our experience.

CONCLUSION

This less invasive technique for the radial artery harvesting appears to be an excellent surgical compromise between the open technique and the endoscopic procedure; it is easy to perform, the learning curve is acceptable and it offers an excellent aesthetic result.

Pre-operative balloon counterpulsation and off-pump coronary surgery for high-risk patients

Coronary artery bypass surgery (CABG) can be performed less invasively without cardiopulmonary bypass (CPB). Multivessel off-pump CABG (OPCAB) is challenging in patients with critical left main stenosis (> 70%) and/or severe ventricular dysfunction (ejection fraction < 0.35) Our objective was the evaluation of efficiency of intra aortic balloon pump (IABP) preoperatively in this high-risk group in order to perform OPCABG safely.

MATERIAL AND METHOD

In a consecutive 10-month period (out of 88 OPCABG patients) 23 high-risk patients were treated and were compared with 15 on-pump patients (out of 69) with the same criteria.

RESULTS

Preoperative implantation of IABP was significantly higher in the OPCABG group (70% vs 46%, p < 0.05). No conversion to CPB was required in the OPCABG group. Post-operative angiography was systematically performed and demonstrated 97.5% patency of anastomosis. No device-related complications occurred. No difference was found concerning age, risk factors, emergency surgery, ejection fraction, mean number of grafts per patient (2.64 versus 2.75) and average operating time. In contrast, OPCABG demonstrated a trend toward reduced morbidity in terms of atrial fibrillation, reexploration for bleeding and prolonged ventilator requirement > 12 h. Mortality was less in the OPCABG group (p < 0.05).

CONCLUSION

More randomized controlled trials are needed to evaluate the true efficacy of elective IABP in OPCABG high-risk patients. Until such studies are evaluated, and therefore because older and sicker patients now constitute a greater percentage of candidates for OPCABG, the timing of application of the IABP is warranted. These results may further justify preoperative use of the IABP in a large proportion of this group of patients.

[Severe intoxication with cardiotoxic drugs: value of emergency percutaneous cardiocirculatory assistance]

Acute severe self-administration of an overdose of betablockers, calcium antagonists or antiarrhythmic drugs is rare but carries a mortality of 10-15%. Between May 1997 and March 2000, 6 patients with an average age of 34 years (range 17-55 years) had a cardiac arrest on admission requiring emergency cardiac massage and emergency intubation with ventilatory assistance following massive ingestion of cardiotoxic drugs. Echocardiography confirmed complete biventricular akinesia. The surgical team implanted a cardiovascular assist device (ECMO: Extra Corporeal Membrane Oxygenation) by the femoral approach with pre-heparinated percutaneous cannula. The first two patients died of multi-organ failure due to a delay in the installation of the assistance. The 4 other patients survived without sequellae or recurrences. The average time on ECMO was 59.25 +/- 2 hours (range 48-71 hours). The early recognition of the indication for ECMO was one of the most important predictive factors for morbidity and mortality. The strategy of patient management should be determined in the emergency room: in cases of cardiocirculatory arrest resistant to symptomatic treatment (stomach washout, intravenous fluids, isoprenaline, inotropic agents) an echocardiogram should be obtained and the cardiac surgical team alerted to the problem. The introduction of pre-heparinated circuits, percutaneous cannula and peripheral shunts has widened the indications, efficacy (detoxification, restoration of peripheral tissue perfusion) and accessibility to this material, while limiting its duration. The collaboration of experienced multidisciplinary teams (emergency room staff, cardiologists, anaesthetists and surgeons) should optimise the timing of implantation and the monitoring of these systems and improve the results of resuscitation of these patients.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

Analysis of arylsulfatases A and B, acid phosphatase, lactate dehydrogenase, and aspartate transaminase in chronic periapical lesions of endodontic origin

Attempts were made to detect and measure the activities of arylsulfatases. A&B acid phosphatase, lactate dehydrogenase, and glutamate oxaloacetate transaminase (aspartate transaminase) enzymes in human chronic lesions of endodontic origin. Thirteen periapical lesions of endodontic origin and 11 noninflamed control periapical tissues were obtained. The specimens were carried to the laboratory on liquid nitrogen and kept at -70 degrees C. Samples were thawed, homogenized, and then assayed for enzyme activities. The specific activities of arylsulfatase A (nmol/hr/mg protein) were 55.0+/-10.7 (chronic lesions) vs. 3.4+/-2.2 (controls) (p < 0.01). Arylsulfatase B specific activities (nmol/hr/mg protein) were 50.3+/-6.4 (chronic lesions) vs 91.8+/-18.4 (controls). Total acid phosphatase activities (mU/mg protein) were 45.8+/-6.6 (chronic lesions) vs. 26.8+/-3.1 (controls). Lactate dehydrogenase activities (Berger-Broida units/mg protein) of the chronic periapical lesions were significantly higher than the control group (362+/-63.2) vs. (140+/-46.0) (p < 0.05). There was no significant difference between the specific activities of aspartate transaminase in chronic lesions and the control group (68.0+/-14.5) vs. (53.0+/-10.4) mU/mg protein).

Aortic root remodeling with the "cuff" technique for stentless valve implantation

Aortic root and sinotubular junction dilatation and aneurysm of ascending aorta are considered relative contra-indications to implantation of a stentless valve prosthesis, because the modified aortic geometry leads to aortic incompetence and early failure of the prosthesis. Aortic root reconstruction can be performed according to various techniques. We present a surgical technique in which a tubular graft, replacing an ascending aortic aneurysm, allows sinotubular remodeling and satisfactory implantation of a stentless prosthesis. The native aorta is inserted into the vascular prosthesis at the level of the sinotubular junction which is wrapped in order to prevent commissure spreading. Sizing of the vascular and valve prosthesis is made according to annular diameter. Since October 1999, 6 patients have been operated using this technique with good results.

Catastrophic consequences of a free floating thrombus in ascending aorta

Floating masses in ascending aorta are an uncommon source of embolism. We report the case of a 46-year-old woman, smoker, on synthetic progestagen, with no previous history of thrombotic events, who was admitted to our emergency department for an acute anterior myocardial infarction. Coronary angiogram showed occlusion of left main coronary trunk. Recanalization of the artery was obtained. Ascending aorta angiogram revealed a free floating mass attached to the aortic wall without evidence of aortic dissection. Transesophageal echocardiography confirmed the presence of a pedunculated mobile mass attached to the aortic wall superior to the left coronary ostium. The patient underwent urgent surgery. Intraoperatively a floating thrombus was localized in the posterior wall of ascending aorta. At macroscopical examination aortic wall and leaflets were normal. Post-operative low cardiac output refractory to inotropic drugs and intraaortic balloon counterpulsation required a circulatory assist device. Consequences for the patient were catastrophic in terms of outcome.

Necrotizing granulomata of the aortic valve in Wegener's disease

Wegener's disease is an inflammatory disease of unknown etiology, characterized by a granulomatous-necrotizing general vasculitis. Cardiac involvement in the form of aortic pathology is not frequent. We report a case of Wegener's granulomatosis which required prosthetic aortic valve replacement for aortic valve insufficiency. Microscopic examination of the valve demonstrated histopathology typical of Wegener's disease.

Surgical treatment of pulmonary aspergilloma: current outcome

OBJECTIVE

This retrospective study was designed to confirm that aggressive pulmonary resection can provide effective long-term palliation of disease for patients with pulmonary aspergilloma.

METHODS AND RESULTS

From 1959 to 1998, 84 patients underwent a total of 90 operations for treatment of pulmonary aspergilloma in the Marie-Lannelongue Hospital. The mean follow-up period was 9 years, and 83% of the patients were followed up for 5 years or until death, if the latter occurred earlier. The median age was 44 years. The most common indications were hemoptysis (66%) and sputum production (15%). Fifteen patients (18%) had no symptoms. Tuberculosis and lung abscess were the most common underlying causes of lung disease (65%). The procedures were 70 lobar or segmental resections, 8 cavernostomies, and 7 pneumonectomies. Five thoracoplasties were required after lobectomy (3 patients) or pneumonectomy (2 patients). The operative mortality rate was 4%. The major complications were bleeding (23 patients), prolonged air leak (31 patients), respiratory failure (10 patients), and empyema (5 patients). The actuarial survival curve showed 84% survival at 5 years and 74% survival at 10 years. During the first 2 years, death was related to the surgical procedure and the underlying disease. In contrast, 85% of the survivors had a good late result.

CONCLUSION

Lobar resection in both the symptomatic and the asymptomatic patients was conducted in low-risk settings. For patients whose condition is unfit for pulmonary resection, cavernostomy may need to be undertaken despite the high operative risk. The better survival rate in this study may have been due to the selection of patients with better lung function and localized pulmonary disease.

Postinfarction ventricular septal rupture: early repair through the right atrial approach

OBJECTIVE

Early repair of posterior ventricular septal rupture associated with myocardial infarction by means of transinfarct ventriculotomy is technically challenging and can be associated with significant mortality and morbidity. An alternative route of exposing the septum is through the right atrium. This technique, which avoids direct incision of the ventricle in select patients, reduces postrepair bleeding and impairment of ventricular contractile function.

METHODS

The results of 12 patients operated on over a 20-year period were reviewed and analyzed. Late follow-up was obtained in all patients who survived the operation. There were 9 men and 3 women, with a mean age of 69.9 years. The mean time between acute myocardial infarction and surgery was 7.3 days (range, 2-16 days). Six patients were in New York Heart Association class IV, and 3 patients presented for surgery in cardiogenic shock. One patient had previously undergone a coronary artery bypass. The surgical technique included a standard sternotomy approach with a transatrial approach to the septal rupture. In all patients the septal rupture was repaired with a Dacron patch.

RESULTS

There were 3 early deaths and 1 late death; one patient was reoperated on for a residual shunt. Postoperative complications included low cardiac output, acute renal tubular necrosis, and supraventricular arrhythmia. Eight patients are alive and undergoing echocardiographic investigation, and only 1 patient had a small residual shunt.

CONCLUSION

Our experience shows that a posterior ventricular septal rupture can be safely repaired through a transatrial approach. Avoiding additional damage to the ventricle, it reduces the risks of the postoperative bleeding and enhances survival.

In vitro effects of desflurane, sevoflurane, isoflurane, and halothane in isolated human right atria

BACKGROUND

Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro.

METHODS

Human right atrial trabeculae, obtained from patients undergoing coronary bypass surgery, were studied in an oxygenated (95% O2-5% CO2) Tyrode's modified solution ([Ca2+]o = 2.0 mM, 30 degrees C, stimulation frequency 0.5 Hz). The effects of equianesthetic concentrations (0.5, 1, 1.5, 2, and 2.5 minimum alveolar concentration [MAC]) of desflurane, sevoflurane, isoflurane, and halothane on inotropic and lusitropic parameters of isometric twitches were measured.

RESULTS

Isoflurane, sevoflurane, and desflurane induced a moderate concentration-dependent decrease in active isometric force, which was significantly lower than that induced by halothane. In the presence of adrenoceptor blockade, the desflurane-induced decrease in peak of the positive force derivative and time to peak force became comparable to those induced by isoflurane. Halothane induced a concentration-dependent decrease in time to half-relaxation and a contraction-relaxation coupling parameter significantly greater than those induced by isoflurane, sevoflurane and desflurane.

CONCLUSIONS

In isolated human atrial myocardium, desflurane, sevoflurane, and isoflurane induced a moderate concentration-dependent negative inotropic effect. The effect of desflurane on time to peak force and peak of the positive force derivative could be related to intramyocardial catecholamine release. At clinically relevant concentrations, desflurane, sevoflurane, and isoflurane did not modify isometric relaxation.

Cosmetic aspects in minimally invasive cardiac surgery

The initial focus of the pioneering cardiac surgeons was appropriately centered on survival as opposed to cosmetic results. A variety of minimally invasive techniques have been introduced to perform cardiac operations through a limited incision. As the results in cardiac surgery improved, cosmetic and psychological implications of surgery become more important in the evaluation of the morbidity of these procedures. Future comparative studies will be mandatory to show whether these small incisions have an actual advantage on recovery or morbidity or whether their interest is entirely aesthetic.

Aortic balloon entrapment complicating intra-aortic balloon counterpulsation

Short-term balloon counterpulsation may be complicated by aortic balloon entrapment. We report a patient in whom video-coronary surgery was performed using beating heart anastomosis. This patient developed intra-aortic balloon (IAB) entrapment 4 days after initiation of the counterpulsation previously implanted for a preoperative low ejection fraction. No limb ischaemia was detected, but urgent removal of the balloon catheter is mandatory if blood is detected in the tubing connecting the balloon to the console, even in the presence of adequate function of the IAB assistance.

A special adapted retractor for the mini-sternotomy approach

Minimally invasive cardiac operations are now possible through different approaches. To provide the best exposure and sufficient space to manipulate the heart, a special adapted thoracic retractor has been developed for the ministernotomy approach. It is universally adjustable and provides excellent and consistent exposure especially below the incision edges. The retractor has the further advantage of a very low profile on the surgeon's side and at the cephalic and caudal extremes of the operative field, which permits the greatest possible access through a limited access. We have successfully used this retractor in more than 180 patients. A less invasive median sternotomy through a 6-9-cm incision has been our original approach.

Comparison of Effects of Acidic Electrolyzed Water and NaOCl on Tilletia indica Teliospore Germination

Definitive identification of free teliospores of Tilletia indica, causal agent of Karnal bunt of wheat, requires polymerase chain reaction (PCR)-based diagnostic tests. Since direct PCR amplification from teliospores has not been reliable, teliospores first must be germinated in order to obtain adequate DNA. We have routinely surface-sterilized teliospores for 2 min with 0.4% (vol/vol) sodium hypochlorite (NaOCl) to stimulate germination and produce axenic cultures. However, we observed that some spores were killed even with a 2-min NaOCl treatment, the shortest feasible duration. Decreasing the NaOCl concentration in our study from 0.4% to 0.3 and 0.2%, respectively, increased teliospore germination, but treatment times longer than 2 min still progressively reduced the germination percentages. In testing alternative methods, we found "acidic electrolyzed water" (AEW), generated by electrolysis of a weak solution of sodium chloride, also surface-sterilized and increased the rate of T. indica teliospore germination. In a representative experiment comparing the two methods, NaOCl (0.4%) for 2 min and AEW for 30 min increased germination from 19% (control) to 41 and 54%, respectively, by 7 days after treatment. Because teliospores can be treated with AEW for up to 2 h with little, if any, loss of viability, compared with 1 to 2 min for NaOCl, treatment with AEW has certain advantages over NaOCl for surface sterilizing and increasing germination of teliospores of suspect T. indica.

Non-penetrating subclavian artery trauma: management by selective transluminally placed stent device

Non-penetrating injury to the subclavian artery has not often been reported. The limited experience of surgeons with this type of trauma and the difficult vascular control required for its management make it a surgical challenge. We report on two cases, one after blunt trauma and the other with a subclavian artery aneurysm following anterior dislocation of the shoulder. Percutaneous stent implantation in the subclavian artery was successfully performed with, in the second case, coil embolization of the aneurysm. Follow-up Doppler sonography and angiogram demonstrated patency and luminal integrity of the involved artery. This less invasive procedure may be a significant advance and a new approach in the conservative management of traumatic subclavian injury for selected cases.

Minimally invasive internal thoracic artery harvest: the hybrid approach

BACKGROUND

Safe harvesting of the left internal thoracic artery is a difficult problem during minimally invasive coronary artery bypass grafting without cardiopulmonary bypass. A complete internal thoracic artery dissection through a limited approach is technically demanding and time consuming and different techniques have been proposed.

METHODS AND RESULTS

Based on our experience, the different surgical approaches and technical considerations are reviewed.

CONCLUSIONS

A hybrid technique using dissection under direct vision and completed by thoracoscopy is discussed and proposed as our preferred technique of internal thoracic artery harvesting.

Spontaneous native aortic valve thrombosis

Spontaneous thrombosis of a native aortic valve is an uncommon event that usually follows local trauma, such as cardiac surgery or left heart catheterization, or occurs as a complication of bacterial endocarditis. We report the case of a 65-year-old woman with a history of retinal artery occlusion and severe aortic valve stenosis, in whom transesophageal echocardiography revealed a mobile mass attached to the ventricular surface of the aortic valve. There was no evidence of any hypercoagulable state or infection process. Surgery was performed and a severely stenotic valve resected; a partially organized and firmly adherent free-floating thrombotic mass was observed on the ventricular surface of the aortic valve. Histologic examination demonstrated an organized thrombus. Eleven months after surgery the patient is doing well.

Secondary leukemia or myelodysplastic syndrome after treatment with epipodophyllotoxins

PURPOSE

The incidence of secondary leukemia after epipodophyllotoxin treatment and the relationship between epipodophyllotoxin cumulative dose and risk are not well characterized. The Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) has developed a monitoring plan to obtain reliable estimates of the risk of secondary leukemia after epipodophyllotoxin treatment.

METHODS

Twelve NCI-supported cooperative group clinical trials were identified that use epipodophyllotoxins at low (<1.5 g/m2 etoposide), moderate (1.5 to 2.99 g/m2 etoposide), or higher (> or =3.0 g/m2 etoposide) cumulative doses. Cases of secondary leukemia (including treatment-related myelodysplastic syndrome) occurring on these trials have been reported to CTEP, as has duration of follow-up for all patients, thereby allowing calculation of cumulative 6-year incidence rates of secondary leukemia for each etoposide dose group.

RESULTS

The calculated cumulative 6-year risks for development of secondary leukemia for the low, moderate, and higher cumulative dose groups were 3.3%, (95% upper confidence bound of 5.9%), 0.7% (95% upper confidence bound of 1.6%), and 2.2%, (95% upper confidence bound of 4.6%), respectively.

CONCLUSION

Within the context of the epipodophyllotoxin cumulative dose range and schedules of administration encompassed by the monitoring plan regimens, and within the context of multiagent chemotherapy regimens that include alkylating agents, doxorubicin, and other agents, factors other than epipodophyllotoxin cumulative dose seem to be of primary importance in determining the risk of secondary leukemia. Data obtained by the CTEP secondary leukemia monitoring plan support the relative safety of using epipodophyllotoxins according to the therapeutic plans outlined in the monitored protocols.

Pulmonary artery bullet injury following thoracic gunshot wound

Thoracic trauma occurs frequently but seldom requires surgery (10-20%, [1]). The mortality rate for gunshot wound of the chest varies from 14.3 to 36.8% [2]. We report, herein an example of bullet injury to the pulmonary artery (PA) following a thoracic gunshot wound. This patient had previous history of coronary surgery. Absolute and relative indications for exploratory thoracotomy in emergency will be reviewed.

Recurrent left-sided heart leiomyosarcoma: should heart transplantation be legitimate?

Leiomyosarcoma of the heart is an uncommon primary malignant tumor with poor postoperative survival that may be measured in months. A leiomyosarcoma of the left atrium was diagnosed in a 47-year-old man. Initial admission was for acute pulmonary edema requiring emergency surgery. The tumor involved the left atrial cavity, and a radical resection was performed. Six months later an isolated myxomatous recurrence was detected. Heart transplantation was then performed. The patient is in good health 20 months after operation with no evidence of residual disease or recurrence. The literature has been reviewed. Surgical resection is not an adequate treatment for leiomyosarcoma of the left atrium and early heart transplantation probably offers the only hope for these patients.

Minimally invasive coronary surgery: surgical considerations and assessment of cardiac troponin I

OBJECTIVE

Minimally invasive coronary artery bypass grafting (MICABG) using internal thoracic artery (ITA) without median sternotomy and cardiopulmonary bypass (CPB) become a viable option for the management of proximal left anterior descending artery (LAD) disease. Recent studies have demonstrated that cardiac troponine I (cTnI), a new highly specific diagnostic marker of cardiomyocyte damage, is a reliable marker of cardiac ischemia during heart operations under CPB.

METHODS

Between February 1996 and April 1997, 14 patients (10 males, 4 females aged 41-68) underwent MICABG with single-vessel bypass grafting for LAD stenosis (n = 9) or occlusion (n = 5). Video-assisted surgery with left anterior mini-thoracotomy was performed in ten patients and vertical parasternal thoracotomy in the other four. cTnI was measured before LAD occlusion (T0), during anastomosis (T1) and 10 min (T2), 6 h (T3), 24 h (T4), 48 h (T5), 72 h (T6) after coronary reperfusion. Assay methods used a specific enzyme-linked immunosorbent autoanalyzer (Stratus) in peripheral venous blood. Control coronary angiography was performed in all patients.

RESULTS

There were no operative complications, no reoperations for bleeding. cTnI concentrations were expressed in ng/ml +/- SD. Mean cTnI level was <3.85+/-1 ng/ml (range 0-32.8). Values were: T0 = 0, T1 = 0.5+/-0.1, T2 = 1.15+/-0.2, T3 = 2.16+/-0.6, T4 = 1.5+/-0.3, T5 = 0.6+/-0.02, T6 = 0.4+/-0.01. Angiography showed patent grafts in 12 patients. A 'no flow situation' was demonstrated in a cardiac symptom-free patient, with reestablishment of flow on repeat angiogram at 6 months. In the other case, early ITA graft occlusion in a patient with two-vessel disease was correlated with a higher cTnI concentration (17.8 ng/ml). Percutaneous angioplasty was performed on the right coronary artery, complicated with dissection and cardiac failure. This patient died 3 months after the MICABG despite ventricular assist device.

CONCLUSION

cTnI did not increase during and after coronary artery occlusion and local immobilization of the heart. It can be used to evaluate postoperative myocardial damage on the beating heart using MICABG.

Less-invasive heart surgery: the preservation of median approach

OBJECTIVE

Cardiac surgery has been traditionally performed via a median sternotomy incision where a large exposure of the mediastinum assured most of the cardiac procedures. Recently, the concepts of less-invasive surgery, well affirmed in many surgical specialties, led cardiac surgeons to develop limited accesses in coronary, valves and congenital operations.

METHODS

Between January and May 1997, 30 patients were operated on with a less-invasive approach. A short (6-9 cm) median incision followed by a subcomplete sternotomy permitted a limited opening of the chest without compromising the surgical exposure; a conventional central CPB was instituted and valve surgery and most of intracardiac procedures were performed without modification of the standard technique.

RESULTS

No mortality was observed; morbidity was minimal. Cardiopulmonary bypass time and aortic cross-clamp time averaged 84+/-9 and 61+/-11 min, respectively. The majority of patients were extubated and discharged from the ICU early. Chest drainage lost on average 290+/-180 ml/m2.

CONCLUSIONS

Despite our limited initial experience, this technique seems to provide several potential and practical advantages: there is less trauma and pain reported by patients; the small wound reduces the potential for wound infection and blood loss. Patients are extubated and discharged from the hospital earlier with lower overall costs.

Less invasive cardiac operations through a median sternotomy: 100 consecutive cases

BACKGROUND

In the beginning of 1997, we developed a routine approach to intracardiac operations through a less invasive median sternotomy. A limited (6 to 9 cm) median skin incision followed by a subcomplete (manubrium and body) median sternotomy makes opening and closing of the chest easier; conventional central cardiopulmonary bypass is instituted, and no modifications to the surgical techniques are necessary.

METHODS

In 100 consecutive patients (mean age, 62.04 years; range, 9 to 92 years), 70 aortic, 13 mitral, and 17 other cardiac procedures were performed. Surgical technique required many self-made instruments; anesthetic "fast-tracking" management was performed.

RESULTS

Four patients died. One conversion to a standard sternotomy and five reoperations for bleeding were necessary. Cross-clamp time ranged from 33 to 140 minutes (mean +/- standard deviation, 69.23 +/- 20.99 minutes) and total drainage loss ranged from 120 to 1,800 mL x m(-2) x 24 h(-1) (mean, 288 mL x m(-2) x 24 h(-1)). The postoperative course was shorter than usual, and one complication in the healing wound was observed. The scar was shorter than 9 cm in all patients.

CONCLUSIONS

Our work shows that a less invasive approach to many cardiac operations is possible through a modified median sternotomy. This technique provides many potential and practical advantages: there is less trauma and pain reported by patients, and the small wound reduces the risk of infection and blood loss. Patients are extubated and discharged from the hospital earlier.

Modified biatrial approach for the extensive resection of left atrial myxomas

Surgical excision of left atrial myxomas is usually curative. When the root of the pedicle and the full thickness of the adjacent interatrial septum are excised, the repair of the created atrial septal defect requires a pericardial or Dacron patch. The biatrial approach generally has been accepted as the technique having the advantages of well identifying the site of attachment and inspection of the four cardiac chambers. We proposed a modification of this technique that allows the reconstruction of the created septal defect without any foreign patch.

[Leiomyosarcoma of the heart and great vessels]

Leiomyosarcomas (LMS) of the heart are exceptional primary malignant tumours with a catastrophic prognosis and a mean survival measured in months. Extensive radical surgical resection clearly remains the most appropriate treatment. We report three cases observed over a 3-year period, consisting of an LMS of the inferior vena cava, an LMS of the pulmonary artery trunk and an LMS of the left atrium. The first case was treated by radical resection and reconstruction by autologous vein graft of the cavorenal junction, the second case was treated by extensive resection and prosthetic reconstruction of the pulmonary artery bifurcation and the third case was treated by a first radical resection of the left atrium, requiring total cardiectomy and orthotopic heart transplantation for local recurrence at the sixth month. The survical was significantly improved compared to other treatment options (chemotherapy, radiotherapy). The first patient is still alive without recurrence at two years; the second died 12.5 months after the surgical procedure and the medium-term follow-up of the transplanted patient revealed cerebral and hepatic metastases nine months after transplantation. The authors review the literature concerning these extremely rare malignant tumours. Recent progress of diagnostic investigations, such as spiral CT with reconstruction, MRI, positron emission tomography (PET), are now able to establish the diagnosis more rapidly and therefore allow more radical surgical resection. This resection, possibly combined with venous reconstruction, must be associated with adjuvant therapies. Heart transplantation should be considered among the treatment options for leiomyosarcomas of the heart, in order to improve the poor prognosis of these lesions affections a young population.

Safety of beating heart anastomosis during video-assisted coronary surgery attested by cardiac troponin I

Our objective was to evaluate the safety of coronary anastomosis on the beating heart by measuring the release of cardiac troponin I during minimally invasive coronary artery bypass grafting (MICABG). Cardiac troponin I (cTnI) is a reliable marker of cardiac ischemia during heart operations under cardiopulmonary bypass (CPB). Ten patients (8 males and 2 females, aged 41-63) underwent MICABG with single vessel bypass grafting for left anterior descending coronary artery (LAD) stenosis (n = 7) or occlusion (n = 3). Video-assisted surgery with left anterior minithoracotomy was performed in all patients. Serial venous blood samples were collected for measurement of cTnI before LAD occlusion (T0), during anastomosis (T1) and 10 min (T2), 6 h (T3), 24 h (T4), 48 h (T5), and 72 h (T6) after coronary reperfusion. The assay method used a specific enzyme-linked immunosorbent Stratus autoanalyzer. Control coronary angiography was performed in all patients. There were no operative complications or reoperations for bleeding. The cTnI concentrations were expressed in ng/ml +/- SD. The mean cTnI level was less than 3.05 +/- 0.2 ng/ml (range 0-32.8). Values were T0 = 0, T1 = 0.4 +/- 0.03, T2 = 1.15 +/- 0.2, T3 = 2.16 +/- 0.6, T4 = 1.5 +/- 0.3, T5 = 0.6 +/- 0.02, and T6 = 0.4 +/- 0.01. Angiography showed patent grafts in 9 patients. In one case, early internal thoracic artery (ITA) graft occlusion in a patient with 2 vessel disease was correlated with a higher cTnI concentration (17.8 ng/ml). Percutaneous angioplasty was performed on the right coronary artery, complicated with dissection and cardiac failure. This patient died 3 months after the MICABG despite support from a ventricular assist device. In conclusion, collateral circulation developed in the setting of chronic coronary occlusion may be efficient for myocardial preservation during short periods such as coronary anastomosis. cTnI immunoassay confirmed the safety of coronary anastomosis on the beating heart during minimally invasive coronary operations.

Bicarbon valve -- European multicenter clinical evaluation

OBJECTIVE

Fifteen collaborating centers in eight countries present their pooled experience with the new Bicarbon bileaflet valve.

METHODS

Between 4/90 and 4/96, 1351 patients, 806 males and 545 females, aged 10 to 83, mean 58.4 +/- 12.4, underwent valve implantation.

OPERATIONS

aortic valve replacement (AVR), 726; mitral valve replacement (MVR), 475; double valve replacement (DVR), 150. Additional procedures: CABG, 211; TV repair, 64; other, 152.

RESULTS

Mortality: 67 early (seven valve related) and 56 late (40 valve related). Valve thrombosis: six obstructive, three non-obstructive; embolism: nine major cerebral, 37 other. Major bleeding: 29. Hemolysis: two clinically significant. Non-structural dysfunction: 24 paravalvular leaks, one leaflet interference. No structural failure! Endocarditis: 24. Reoperation 48: 22 non-structural dysfunctions, 14 endocarditis, seven thrombosis and embolism, five other. Estimated 5-year freedom from valve-related deaths is 97.2% for AVR and 92.4% for MVR; 4-year freedom from valve related deaths for DVR is 90.5%. Mean calculated NYHA improvement is 1.24.

CONCLUSIONS

The Bicarbon mechanical prosthesis is well designed, durable, has good hemodynamic features and an acceptably low incidence of complications.