Do on- and off-pump coronary bypass surgery differently affect perioperative peripheral tissue metabolism?

BACKGROUND: Microdialysis allows the in-vivo assessment of interstitial fluids. We studied the metabolic status of peripheral tissues (skeletal muscle) in patients undergoing coronary artery bypass surgery on- (CABG) or off-pump (OPCAB). METHODS: Twenty patients candidates to elective coronary bypass surgery were randomly assigned to undergo CABG or OPCAB. A microdialysis catheter was inserted in the left deltoid muscle before surgery and left in place for 24 hours, and metabolic markers of peripheral tissue perfusion (glucose, lactate, pyruvate, glycerol and lactate/pyruvate (L/P) ratio) were assessed before, at the end, and 24 hours after surgery. RESULTS: Preoperative clinical features were similar in both groups. Interstitial levels of glucose and lactate increased over time, being in both groups significantly higher than baseline 24 hours after surgery, whereas glycerol levels did not change over time and between groups. In addition, there was an increase over time of pyruvate levels which were significantly higher in CABG after surgery, whereas L/P ratio was significantly higher in OPCAB 24 hours after surgery. CONCLUSION: Metabolic changes after coronary bypass surgery occur with some differences related to CPB use. Overall, these changes suggest that, after coronary surgery, a certain degree of hypermetabolic state ensues, lasting up to 24 hours after surgery; the postoperative increase in pyruvate levels in CABG patients, together with the changes in L/P ratio occurring only in OPCAB patients implies an higher risk of tissue hypoperfusion/ischemia for patients submitted to OPCAB, although this does not lead to permanent cellular damage, as the markers of this complication (e.g., glycerol) do not change over time.

Severity of periodontal disease correlates to inflammatory systemic status and independently predicts the presence and angiographic extent of stable coronary artery disease.

BACKGROUND: Periodontal disease (PD) has been recognized as a risk factor for systemic diseases, but its involvement in the pathogenesis of coronary artery disease (CAD) remains debated. OBJECTIVES: We sought to evaluate the potential relations between severity of the PD, inflammatory response and angiographic lesions extent in patients with stable CAD. DESIGN: A total of 131 subjects referred to our centre for coronary angiography were evaluated for presence and extension of CAD, then divided into two groups, one with presence of lesions (cases, n = 85) and other one with absence of lesions (controls, n = 46). Mean periodontal pocket depth (PPkD), high sensitivity C reactive protein (hs-CRP), serum amyloid A protein (SAA) and fibrinogen levels were measured in all patients. RESULTS: Cases and controls did not differ according to their baseline characteristics and prevalence of traditional cardiovascular risk factors. PPkD was greater in patients with CAD than in controls (2.24 +/- 1.28 mm vs 1.50 +/- 0.93 mm, P < 0.001 by Student's t-test). Systemic inflammatory response was more pronounced in cases than in controls, with higher values of hs-CRP, SAA and fibrinogen. Furthermore, PPkD values correlated with hs-CRP (r = 0.80, P < 0.001), SAA (r = 0.71, P < 0.001), fibrinogen levels (r = 0.72, P < 0.001) and the American College of Cardiology/American Heart Association angiographic score (r = 0.68, P < 0.001) in cases. Multivariate analysis indicated a persistent independent correlation between PPkD and angiographic score after adjustment for inflammatory markers levels. CONCLUSION: In the present study, PD lesions predicted presence of CAD stenosis in patients with cardiovascular risk factors. PD severity was correlated to angiographic extent of coronary lesions, independent of systemic inflammatory status. Those results suggest that these patients might benefit from an intensive periodontal therapy to prevent CAD progression.

Accidental ingestion and aspiration of root canal instruments and other dental foreign bodies in a French population.

AIM: To determine the incidence of aspiration and ingestion of endodontic instruments in France during root canal treatment without using rubber dam. METHODOLOGY: Data was provided by two insurance companies representing 24,651 French general dentists over 11 years. The type and number of accidents per year, the number of dental items involved and the percentage of occurrence of either aspiration or ingestion were reported. The incidence of accidental aspiration or ingestion was calculated. The need for hospitalization to remove the endodontic instruments and other dental items was reported and compared using chi square tests. RESULTS: One endodontic instrument was aspirated and 57 were ingested. Forty-three other dental items were aspirated and 409 were ingested. For the endodontic instruments: the incidence of aspiration was 0.001 per 100,000 root canal treatments and the incidence of ingestion was 0.12 per 100,000 root canal treatments. The aspirated endodontic instruments and dental items required statistically more frequent hospitalization than the ingested items (P < 0.0001). The endodontic instruments did not require more frequent hospitalization than other dental items when aspirated (ns) and when ingested (ns). No fatal outcome was reported. CONCLUSION: The incidence of ingestion or aspiration of endodontic instruments was low even thought most general practitioners do not routinely use rubber dam. Use of rubber dam by general practitioners for endodontic procedures should be encouraged by stressing its advantages rather than the fear factor of accidents.

Cytotoxicity of Epiphany and Resilon with a root model.

AIM: To record the cytotoxicity of Resilon and Epiphany (Pentron clinical technologies, Wallingford, CT, USA) using a root model. METHODOLOGY: Thirty teeth with single roots were sectioned at the enamel-cementum junction, the root canals prepared and each root then sterilized before filling with the lateral condensation technique using one of three filling materials (n = 10 per group): Resilon and Epiphany, Sealite (Septodont, Pierre Rolland, Merignac, France) and gutta-percha, Roekoseal Automix (Coltène/Whaledent, Langenau, Germany) and gutta-percha. The roots were stored at 37 degrees C in an incubator to allow for setting of the root filling materials. The apices of the roots were dipped in 1 mL of MEM culture medium for 1, 2, 7 and 30 days renewing the medium every day. After 24 h contact between the medium and the filled roots, the medium was used to measure the cytotoxicity on mouse fibroblasts L 929 with the MTT assay that recorded the mitochondrial activity of the target cells. An additional test according to ISO 10993-5 standards was undertaken to compare Resilon and Epiphany. RESULTS: The root model showed no statistically significant differences between the sealers at 7 and 30 days (NS). Epiphany and Resilon were the most cytotoxic materials at 1 and 2 days (P < 0.001). Unlike Epiphany, Resilon was not cytotoxic when tested according to ISO 10993-5 standards. CONCLUSIONS: The cytotoxicity of Resilon + Epiphany, due mainly to Epiphany, decreased after 2 days to reach a level comparable with commonly used root canal sealers.

[Care of handicapped children under general anesthesia in relation to different clinical parameters. Preliminary notes]. / Prise en charge des enfants handicapés sous anesthésie générale. Lien avec différents paramètres cliniques. Notes préliminaires.

Losses of teeth are significant and frequent among handicapped patients. For this study a sample of 58 children handicapped out of the 412 children dealt with for preserving dental care under general anaesthesia, was analyzed. If at equal age these children present a CAD on permanent teeth more significant, their undertake, the procedure of general anaesthesia and the preserving treatments under general anaesthesia do not present more difficulties than the child is handicapped or not. The factor determining in the effectiveness and the speed of the exempted acts seems to be the training of the dental care team.

[Care of handicapped children under general anaesthesia. Relationships with various clinical parameters. Preliminary notes]. / Undertake handicapped children under general anaesthesia. Link with various clinical parameters. Preliminary notes.

Losses of teeth are significant and frequent among handicapped patients. For this study a sample of 58 children handicapped out of the 412 children dealt with for preserving dental care under general anaesthesia, was analyzed. If at equal age these children present a CAD on permanent teeth more significant, their undertake, the procedure of general anaesthesia and the preserving treatments under general anaesthesia do not present more difficulties than the child is handicapped or not. The factor determining in the effectiveness and the speed of the exempted acts seems to be the training of the dental care team.

Oral functional characteristics and gastrointestinal pathology: an epidemiological approach.

One of the main problems for aged people is that of having a balanced diet, improved by correct conditioning of the alimentary bolus. Does the masticatory status influence the appearance of gastrointestinal disorders? Such a question justifies the present study. The present work concerned all the patients (211) of eight geriatric institutions, and was completed by a retrospective approach (case-control study). The main result brought by the case-control study, showed that poor oral functional characteristics represent a risk for gastrointestinal pathology (age being neutralized; odds ratio (OR): 2.62). This result indicates that the loss of teeth must be compensated by functionally effective dentures. Not only will the patients' physical and psychic health improve but also medical and public health problems will be solved.

Learning curve for translaryngeal tracheotomy in head and neck surgery.

OBJECTIVES: Translaryngeal tracheotomy (TLT) is a widely accepted procedure in intensive-care units for its simplicity of execution, low morbidity, rapid wound closure after cannula removal, good esthetic results, and lack of long-term sequelae. The aim of this study was to evaluate the feasibility and use of adopting TLT in patients with cancer undergoing major head and neck surgery. STUDY DESIGN: Prospective analysis of learning curve and incidence of complications in 41 patients with cancer who underwent TLT at the Division of Head and Neck Surgery of the European Institute of Oncology from November 1997 to June 1999. METHODS: Patient characteristics, pathology, anatomic characteristics of the neck, and surgical short-term and long-term complications were noted. The patients were divided into consecutive groups of six or seven patients, and time trends in occurrence of complications and time to execute the procedure were assessed. RESULTS: TLT performance time decreased from 50 minutes in the first seven patients to 24 minutes in the last group. The technique was easy to perform and safe, with only two minor complications during surgery. However, minor complications occurred in three and major complications in 17 patients in the days immediately following surgery, almost entirely attributable to lack of counter-cannula and stylet. CONCLUSIONS: In view of the high proportion of major complications, TLT using the presently available kit is unsuitable for major head and neck surgery. However, the considerable advantages of the technique would recommend it as a valid alternative to surgical tracheotomy if the kit included a counter-cannula and stylet.

Intrapericardial treatment of neoplastic pericardial effusions.

Pericardial effusion and cardiac tamponade are known complications of many advanced malignancies as lung cancer, breast cancer, lymphomas and leukemias. Initial relief can be easily obtained with percutaneous echo-guided pericardiocentesis, without significant mortality and morbidity and well-tolerated even in critically ill patients. Effusion recurrences can be observed, however, in up to 40% of cases if only simple pericardial drainage is performed. Effective management can be obtained by instillation in the pericardial sac of different agents, with sclerosing or cytostatic activity, like tetracyclines, bleomycin, thiotepa or radionuclides. Intrapericardial sclerotherapy is associated to good results in terms of recurrence prevention and survival improvement. Absence of pericardial effusion at 30 days after drainage can be observed in 70 to 90% of all treated patients, without significant variations among different treatments. No significant side effects are observed, with the exclusion of chest pain during tetracyclines instillation. In our opinion pericardiocentesis associated to intrapericardial sclerotherapy with thiotepa is the best compromise in terms of recurrence prevention, tolerability and costs. Real randomized, case-control studies are moreover required to assess the gold standard of malignant pericardial effusions treatment.

[Intra- and extravascular volumes in congestive heart failure and their redistribution following extracorporeal ultrafiltration]. / Volumi intra ed extravascolari nello scompenso cardiaco congestizio refrattario e loro ridistribuzione a seguito di ultrafiltrazione extracorporea.

In advanced congestive heart failure with fluid retention, extracorporeal ultrafiltration (UF) causes persistent relief of edema or anasarca through hemodynamic and humoral changes that interrupt refractoriness to diuretics. The intra and extravascular fluid partition in congestive heart failure, as well as changes occurring in the two compartments following fluid withdrawal with UF, are unknown. In 8 congestive heart failure patients with severe fluid retention undergoing UF, we measured total (TBV), intrathoracic (ITBV) and pulmonary blood volumes (PBV), and extravascular lung water (EVLW). The intra and extravascular volumes were evaluated by a fiberoptic thermal dye dilution monitoring system, before, at the end of UF (3697 +/- 699 ml) and 24 hours later. Baseline data were compared with those of 10 subjects without heart failure undergoing coronary bypass surgery. In congestive heart failure patients, as compared with controls, TBV was normal, the intrathoracic blood content (ITBV, PBV and PBV/TBV ratio) was increased and EVLW was normal. UF did not induce significant changes in TBV and in EVLW, and reduced ITBV, PBV and PBV/TBV ratio, suggesting that a shift of fluid from the intra to the extrathoracic intravascular compartment occurred. Because both TBV and EVLW were not affected by the procedure, the largest proportion of fluid removed by UF derived from the systemic extravascular space. Both pulmonary wedge and right atrial pressures significantly decreased after UF, and cardiac output increased. In conclusion, congestive heart failure is associated with normal TBV and EVLW content and with intravascular intrathoracic hypervolemia and extrathoracic hypovolemia. UF induces hemodynamic improvement through a selective fluid removal from the extravascular systemic space without changes in both TBV and EVLW.

Influences of aortic pressure gradient and ventricular septal thickness with systolic coronary flow in aortic valve stenosis.

This study evaluates flow patterns of the left anterior descending and circumflex coronary arteries by multiplane transesophageal echocardiography in 25 patients with aortic valve stenosis, and assesses the relation between coronary flow characteristics and anatomic and hemodynamic parameters.

Intraoperative phrenic nerve monitoring in cardiac surgery.

BACKGROUND: Left hemidiaphragmatic paralysis due to phrenic nerve lesion is a frequent complication of hypothermic cardiopulmonary bypass. Although this is believed to be caused by cold injury to the phrenic nerve, its exact cause is still not clear. STUDY OBJECTIVE: To assess feasibility, safety, and usefulness of intraoperative phrenic nerve function monitoring. SETTING: Elective cardiac surgery in a university hospital. PATIENTS: Consenting patients scheduled for myocardial revascularization surgery with the use of the left internal mammary artery. DESIGN: Intraoperative monitoring of compound diaphragmatic action potentials (CDAPs) through transcutaneous stimulation of phrenic nerves. INTERVENTIONS: Patients were divided in two groups. Group 1 received intracoronary cold St. Thomas's solution as the only cardioplegic method. Group 2 received topical cardiac cooling with ice-cold solutions in addition to intracoronary cardioplegia. RESULTS: In all group 1 patients, function of phrenic nerves was maintained throughout the surgical procedure. Group 2: in two patients, bilateral, and in one patient, left phrenic nerve conduction was abolished after submersion of the heart in ice-cold solution. In two of them, the action potential of the left hemidiaphragm was absent by the end of surgery. In one, nerve conduction recovered with rewarming of the patient. DISCUSSION: Intraoperative monitoring of CDAP was safe and easily obtained in the intraoperative setting. It allowed us to observe changes in phrenic nerve conduction occurring during surgery and as a result of cold cardioplegia. Cryogenic lesion of phrenic nerve might explain our findings. However, nerve ischemia cannot be ruled out and it may worsen axonal damage or delay its recovery. COMMENT: This monitoring method allowed us to predict postoperative diaphragmatic dysfunction. Also, surgeons can be warned of the damaging effects of excessive cooling of the pericardium and surrounding structures; thus, preventive measures can be taken.

[Circulatory support with Hemopump in cardiogenic shock secondary to papillary muscle rupture]. / Assistenza circolatoria con Hemopump nello shock cardiogeno da rottura di muscolo papillare.

A 71-year-old woman submitted to multiple coronary artery bypass grafts suddenly developed in the third postoperatory day cardiogenic shock. Transesophageal echocardiography examination and color Doppler showed prolapse of the anterior mitral valve leaflet and detached anterolateral papillary muscle in the left atrial cavity with severe mitral valve regurgitation and increased left ventricular wall kynesis. Maximal inotropic and vasodilator support was not effective and a mechanical circulatory assistance was deemed necessary awaiting for mitral valve replacement not performed on emergency for unavailability of operatory rooms. Hemopump pump-cannula assembly was introduced through a femoral graft and the cannula was advanced in the aorta and positioned in the left ventricle across the aortic valve. Pump rate was set at the maximal speed and as an immediate result, mean arterial pressure increased and mean pulmonary pressure decreased. Global cardiac output during 190 min of assistance was 3.48 l/min at a mean arterial pressure of 81 mmHg. The Hemopump provided 3 l/min of flow with an effective left ventricle unloading. The patient subsequently underwent mitral valve replacement and her postoperative outcome was uneventful and free from complications.

Coronary flow and left ventricular diastolic function in aortic regurgitation.

BACKGROUND: An abnormal coronary perfusion pressure is probably the major determinant of altered myocardial perfusion in aortic regurgitation; ventricular hypertrophy and diastolic function may also be involved. This study was undertaken to investigate the respective roles of these two variables. METHODS: Using multiplane transesophageal echocardiography, we evaluated the coronary Doppler flow velocity in the proximal left anterior descending coronary artery in 15 patients with aortic regurgitation before and immediately after valve replacement. The ratios of diastolic:systolic velocity integral and early:late diastolic velocity integral were correlated against coronary perfusion pressure, pulmonary wedge pressure and Doppler echocardiographic indices of left ventricular diastolic function. Patients were compared with 10 subjects without valvular diseases. RESULTS: Aortic regurgitation was associated with a reduction of the coronary diastolic:systolic velocity integral ratio and increment in the early:late diastolic velocity integral ratio. The latter correlated positively with early:late diastolic ratio of mitral flow velocity, pulmonary wedge pressure and left ventricular mass index. Soon after valve replacement, a decrease in pulmonary wedge pressure and a rise in coronary perfusion pressure were seen. Both the echo-Doppler parameters related to diastolic function and the systodiastolic distribution of coronary flow returned to normal. This indicates that diastolic dysfunction rather than left ventricular mass may be related to a disordered myocardial perfusion. CONCLUSIONS: In aortic regurgitation, a relationship exists between diastolic ventricular function and coronary flow phasic distribution. Valve replacement improves the former and normalizes the latter. Echo-Doppler parameters of diastolic dysfunction identify patients with worse coronary perfusion and might represent an additional criterion in the preoperative evaluation of patients with aortic regurgitation.

[Transesophageal coronary flowmetry and ventricular diastolic properties in surgically treated aortic insufficiency]. / Flussimetria coronarica transesofagea e proprietà diastoliche ventricolari nell'insufficienza aortica trattata chirurgicamente.

In patients with aortic valve regurgitation anginal pain without coronary artery disease is a consequence of both impairment of coronary flow (CF) reserve and reduction of diastolic CF (D) due to a diminished coronary perfusion pressure (CPP). Aim of this study was to evaluate with transesophageal multiplane echocardiography CF pattern in 15 patients with severe aortic regurgitation (AR) in the operative room before and after aortic valve replacement and to correlate it with hemodynamic parameters of left ventricular systolic (echocardiographic fractional shortening area) and diastolic (Doppler E/A ratio of mitral flow and X/Y ratio of pulmonary venous flow; pulmonary wedge pressure) function. Patients were compared to a control group (C) of 10 subjects. Coronary flow was divided into systolic (S), protodiastolic (PD) and end-diastolic (ED) components. In AR we observed a reduction in D/S ratio (2.6 +/- 1.3 versus 3.5 +/- 0.8, NS) and an increase in PD/ED ratio (2.24 +/- 2.8 versus 1.05 +/- 0.15, p < 0.001). A positive correlation was observed between PD/ED ratio and left ventricular diastolic impairment (E/A ratio: r = 0.71, p < 0.001; wedge pressure: r = 0.70, p < 0.001) and a negative correlation with CPP (r = -0.6, p < 0.02). Forty-five min after aortic valve replacement diastolic function improvement and CPP increase were associated with a normalization of CF pattern (D/S = 4.35 +/- 1.9/PD/ED = 1.06 +/- 0.16). In conclusion in AR diastolic dysfunction and abnormal CPP are strictly related to the reduction in diastolic CF; valve replacement normalizes the former two parameters and redistributes CF in late diastole.

Preoperative management and surgical therapy in complicated acute infective endocarditis: a 5-year experience.

Twenty-five patients underwent early and elective valve replacement for infective endocarditis during a 5-year period between April 1985 and March 1991. Indications for urgent surgical intervention performed at a mean 32 (range 6-47) days after admission were intractable heart failure, systemic emboli, septic multiorgan failure and the presence of vegetations. Indication for elective surgery was persistent (mean 42 (range 17-56) days) infection after appropriate antibiotic therapy. Twenty patients (80%) had a native valve endocarditis; five (20%) had prosthetic valve involvement. A total of 30 valvular prostheses were implanted: 22 (73.3%) were aortic (21 mechanical and one biological); eight (26.7%) were mitral (all mechanical). All unstable patients referred were treated before surgery in the intensive care unit and subjected to blood ultrafiltration to restore satisfactory circulatory parameters. No patient underwent cardiac catheterization; all patients were operated upon on the basis of echocardiographic data alone. One patient (4%) died during hospitalization; two (8%) died later at 48 and 12 months after the first intervention. The reoperation rate was 12%. After a mean follow-up of 49 (range 1-71) months, 21 of the survivors (95%) were in New York Heart Association functional class I or II; the actuarial 5-year survival rate was 87%. Precise preoperative assessment of early operative indications and timely association of medical therapy in unstable patients could represent a step forward in the treatment of acute infective endocarditis.

Reversal of cardiogenic shock and severe mitral regurgitation through verapamil in hypertensive hypertrophic cardiomyopathy.

A 65-year-old man with long-standing hypertension developed cardiogenic shock due to the onset of left ventricular outflow obstruction and severe mitral regurgitation after surgical repair for abdominal aortic aneurysm. This complication occurred in the early postoperative period and reversed immediately after treatment with intravenous verapamil.

Percutaneous pericardiocentesis versus subxiphoid pericardiotomy in cardiac tamponade due to postoperative pericardial effusion.

In a retrospective study, 42 patients with acute cardiac tamponade due to pericardial effusion were evaluated following cardiac surgery, and the pericardial fluid was drained by one of two alternative methods: two-dimensional echocardiographic-guided pericardiocentesis (2D-echo) or subxiphoid surgical pericardiotomy. During the first period (from 1982 to 1986), one of the two methods was chosen by the treating physicians, whereas in the second period (from 1986 to 1991), 2D-echo-guided pericardiocentesis was the treatment of choice. Percutaneous pericardiocentesis was performed using local anesthesia in 29 patients. A Tuohy needle was inserted at the left xipho-costal junction and, when fluid was obtained, 6 mL of saline solution was injected during 2D-echo contrast monitoring, and a multiple-hole, 6F, 30-cm catheter was inserted by means of a guidewire and positioned into the posterior pericardium, as near as possible to the atrioventricular groove. Complete drainage of pericardial fluid by percutaneous pericardiocentesis was obtained in 26 patients (89%). This procedure also allowed the evacuation of posterior and loculated effusions. Complications included two right ventricular punctures, which were immediately recognized by 2D-echo contrast and produced no serious consequences. Sixteen patients who underwent surgical pericardiotomy had complete evacuation of pericardial fluid without major complications (two of them suffered atrial arrhythmias during the procedure). The average amount of fluid drained, as well as the localization of the effusions, were the same for both groups. 2D-echo-guided pericardiocentesis was found to be a useful, safe, and simple technique. It can be used as an alternative treatment to subxiphoid pericardiotomy for cardiac tamponade due to postoperative pericardial effusions.