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[Re-sternotomy].

The indications and techniques for an pitfalls to avoid which might result in complications after resternotomy are reviewed. The relationship between anterio mediastinal structures and the posterior aspect of the sternum (as visualized on chest, films, CT, or tomography), and other approach(es) including the pros and cons of the contemplated procedure must be assessed carefully. Preparations for emergency F-F cardiopulmonary bypass must be completed before resternotomy. The Wires of the previous operation are undone, but kept in place as safeguards during sternal division using an oscillating (not reciprocating) bone saw. After their removal, the pericardium or other mediastinal structures adhering to the posterior aspect of the sternum are freed before applying a small sternal retractor. The pericardial dissection plane is developed at the cardiophrenic angle, advanced cephalad and laterally on the surface of the right ventricle and atrium. Cephalad dissection starts with imnominate vein identification down the superior vent cave, keeping in mind the location of the right phyenic nerve, and toward the anterior aspect of the great vessels. Repairing small ventricular or aerial lacerations should not be attempted before releasing the tension by sharp dissection of the adhesions surrounding the laceration, and repair of great vessel injuries is best done under cardiopulmonary bypass.

Humans↗

Combined use of single and double-cross steel wires for closure of midline sternotomy.

BACKGROUND: We describe an improved technique for sternal closure which is performed using combined single and double-cross steel wires. We made a mechanical study of these single and double-cross shapes considering the effects of applied transverse and longitudinal shearing forces. METHODS: We used this technique in 80 patients who underwent coronary surgery with the use of bilateral internal mammary arteries. RESULTS: Among them no major wound complications occurred, and in all cases a firm stabilization of the sternum was achieved. CONCLUSIONS: We therefore consider this technique of sternal closure easy, safe and effective, also in patients considered at risk for sternal dehiscence.

Bone Wires↗

Reoperative mitral valve surgery via right thoracotomy: decreased blood loss and improved hemodynamics.

BACKGROUND AND AIMS OF THE STUDY: Reoperative mitral surgery via sternotomy can be associated with significant complications, including excessive blood loss and injuries to the heart, great vessels and patent coronary artery grafts. The right antero-lateral thoracotomy offers excellent exposure with less risk from re-entry. MATERIALS AND METHODS: Between 1982 and 1992, 221 patients had repeat mitral valve procedures at our institution. Fifteen of these 221 underwent mitral valve replacement via right thoracotomy. Indications for surgery in each group included bioprosthetic valve failure, paravalvular leak and bacterial endocarditis. Fifteen patients having reoperative mitral valve surgery via right thoracotomy approach were compared with a control group of 33 patient who underwent surgery via repeat sternotomy. All thoracotomy patients underwent mitral replacement or repair with ventricular fibrillation without aortic cross-clamping. Operative time, cardiopulmonary bypass time, requirement for inotropic support, blood loss within the first six postoperative hours, number of blood units transfused, length of ICU stay, days to discharge, and 30-day survival were compared between the two groups. In addition, the preoperative PaO2/FiO2 (P/F) ratio was evaluated as a prognostic indicator. RESULTS: Bypass time (162 +/- 43 min thoracotomy group vs. 131 +/- 34 min sternotomy group), operative time (389 +/- 100 min thoracotomy group vs. 450 +/- 25 min sternotomy group), ICU stay (6 +/- 8 days thoracotomy group vs. 5 +/- 6 days sternotomy group), P/F ratio (352 +/- 142 thoracotomy group vs. 423 +/- 108 sternotomy group), and 30-day survival (93% thoracotomy group vs. 91% sternotomy group) were not found to be significantly different between groups. Of great significance was the reduction in blood loss (277 +/- 152 ml thoracotomy vs. 651 +/- 504 ml sternotomy, p < 0.05) and blood transfused (2.0 +/- 1.7 units thoracotomy vs. 6.5 +/- 3.3 units sternotomy, p < 0.01) with the thoracotomy approach. Also of significance was a reduction in frequency with which significant inotropic support was needed to separate from cardiopulmonary bypass (26% vs. 63%, p < 0.05). Despite decreased access to the heart for de-airing maneuvers, no cerebrovascular events whatsoever were noted with the thoracotomy approach. CONCLUSION: The right thoracotomy approach is recommended for redo mitral valve surgery. Despite these advantages, severe pulmonary dysfunction (as indicated by a P/F ratio less than 300) correlated with a prolonged hospital course in four thoracotomy patients; such patients should have repeat sternotomy.

Blood Loss, Surgical↗

Robotic minimally invasive mitral valve reconstruction yields less blood product transfusion and shorter length of stay.

BACKGROUND: Robotic-assisted minimally invasive mitral valve reconstruction has gained popularity recently. Initial reports suggest that this approach can be used with relative safety and efficacy. Direct comparisons with a traditional sternotomy approach have not yet been explored extensively. METHODS: All mitral valve procedures that were performed by a single surgeon during a 3-year period of time were analyzed (n = 142 procedures). Patients whose condition required concomitant coronary artery bypass grafting or aortic valve surgery were excluded subsequently from analysis, because all of these patients were approached obligatorily by sternotomy (n = 71 patients). Six patients underwent right thoracotomy mitral valve procedures without robotic assistance, and 1 patient in cardiogenic shock underwent emergent mitral valve reconstruction by sternotomy. Of the remaining 64 patients who were eligible theoretically for sternotomy or robotic-assisted minimally invasive surgery, 39 patients underwent sternotomy, and 25 patients underwent right chest minimally invasive robotic-assisted surgery. Randomization between these 2 approaches would be almost impossible in the United States. The primary determinant for the choice of approach was request of the referring physician or patient. Multiple perioperative outcomes were then compared. RESULTS: Patients who underwent sternotomy and robotic-assisted surgery exhibited equivalent preoperative characteristics and experienced an equivalent degree of correction of mitral regurgitation in repairs and in need for replacement. Complex mitral valve repairs that entailed leaflet resection and reapproximation, annular plication, sliding annuloplasty, chordal transfer, and GoreTex neochordal construction were accomplished successfully with the robotic system. Cross-clamp and bypass times were longer for patients in the minimally invasive group (110 vs 151 minutes; P = .0015; 162 vs 239 minutes; P < .001, respectively). Mean packed red blood cell transfusion was lower among patients who underwent robotic-assisted surgery (5.0 vs 2.8 units; P = .04). Patients who underwent robotic-assisted surgeries experienced shorter mean duration of postoperative hospitalization (10.6 vs 7.1 days; P = .04). There was 1 death among the patients who underwent sternotomy, and no deaths among the patients who underwent robotic-assisted surgery. CONCLUSION: Patients can undergo mitral valve reconstruction with minimally invasive robotic assistance, avoid a sternotomy, require less blood product transfusion, and experience shorter hospitalization.

Cardiopulmonary Bypass↗

[Isoflurane: coronary blood flow and myocardial metabolism in patients with coronary heart disease].

The effects of isoflurane on myocardial oxygen uptake, metabolism and coronary blood flow (argon washin-technique) were studied in 10 patients undergoing three-vessel coronary artery bypass surgery. All patients were men with stable angina and normal left ventricular function and were receiving maintenance doses of beta-receptor antagonists or calcium channel blocking drugs. Anaesthesia consisted of isoflurane and 50% nitrous oxide in oxygen. Measurements were performed and blood samples were taken with the patients awake, 20 min after induction of anaesthesia without surgical stimulation, and during sternotomy and sternal spread. End-tidal isoflurane concentrations averaged 0.4% after induction of anaesthesia and 1.5% during sternotomy. Isoflurane significantly decreased myocardial blood flow by 18% following induction of anaesthesia, while sternotomy increased myocardial blood flow to pre-induction levels. Induction decreased myocardial oxygen uptake by 32%, while sternotomy increased oxygen uptake by 21% vs post-induction values. Myocardial uptake of glucose, lactate, free fatty acids and pyruvate significantly decreased after induction and increased to pre-induction levels during sternotomy. Myocardial lactate production, indicating myocardial ischaemia, was observed in 1 patient after induction and in three patients during sternotomy; three additional patients demonstrated a marked reduction in myocardial lactate uptake after induction and during sternotomy. It is concluded that all changes in myocardial metabolism, oxygen uptake and coronary blood flow were the result of a decrease in haemodynamic load on the myocardium and reduced contractility, while the increase in these parameters during sternotomy was due to an increase in myocardial work.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Accuracy of pulse contour cardiac index measurements during changes of preload and aortic impedance].

BACKGROUND: Cardiac index obtained by arterial pulse contour analysis (CI(PC)) demonstrated good agreement with arterial or pulmonary arterial thermodilution derived cardiac index (CI(TD), CI(PA)) in cardiac surgical or critically ill patients. However as the accuracy of pulse contour analysis during changes of the aortic impedance is unclear, we compared CI(PC), CI(TD) and CI(PA) during changes of preload and the aortic impedance as occurring during sternotomy. PATIENTS AND METHODS: CI(PC) und CI(TD), were compared in 28 patients, (and CI(PA) in 6 patients) undergoing elective coronary artery bypass grafting, before and after sternotomy. The relative changes DeltaCI(PC) und DeltaCI(PC) were calculated. RESULTS: Sternotomy resulted in a significant increase in CI in 25 out of 28 patients. Regression analysis was performed between CI(PC) and CI(TD) before and after sternotomy (r(2) = 0.87, p<0.0001, r(2) = 0.88, p<0.0001) as well as between CI(PC) and CI(PA), before and after sternotomy (r(2) = 0.85, p<0.0001, r(2) = 0.93, p<0.01) and between DeltaCI(PC) and DeltaCI(TD) (r(2) = 0.72, p<0.0001). Bland Altman-Analysis for determining bias (m) and precision (2SD) between CI(PC) and CI(TD) before and after sternotomy and between DeltaCI(PC) and DeltaCI(TD) resulted in m = -0.03 L/min/m(2), 2SD = -0.34 to 0.28 L/min/m(2), m = -0.06 L/min/m(2), 2SD = -0.45 to 0.33 L/min/m(2) and m = -0.02 L/min/m(2), SD = -0.47 to 0.44 L/min/m(2). CONCLUSION: Pulse contour analysis derived CI(PC) accurately reflects thermodilution derived CI(TD) or CI(PA) during changes of preload and the aortic impedance as occurring during sternotomy.

Aged↗

Myocardial circulatory and metabolic effects of halothane when used to control intraoperative hypertension in patients with coronary artery disease.

The effect of halothane on regional myocardial metabolism and blood flow, when used as an adjunct to fentanyl-nitrous oxide anaesthesia, to treat intraoperative hypertension was investigated. Fifteen patients with two- or three-vessel coronary artery disease with an ejection-fraction greater than 0.5 and on beta-blockers up to the morning of surgery were studied during elective coronary artery by-pass grafting. Systemic and pulmonary haemodynamics, global (coronary sinus, CSF) and regional (great cardiac vein, GCVF) myocardial blood flow were measured. Measurements were made: 1) after induction of anaesthesia but prior to skin incision, 2) during sternotomy, and 3) during halothane administration after its use to reduce arterial pressure to the pre-sternotomy level. The increase in systemic arterial pressure during sternotomy was due to an increase in systemic vascular resistance index (SVRI), and was accompanied by an increase in pulmonary capillary wedge pressure (PCWP), regional myocardial oxygen consumption and extraction, GCFV and CSF. Halothane reduced arterial blood pressure to pre-sternotomy levels within 7.1 +/- 0.6 min at an end-tidal concentration of 0.96 +/- 0.11%. Halothane caused a decrease in SVRI, total coronary vascular resistance, regional myocardial oxygen consumption and extraction, while cardiac index, heart rate and GCVF/CSF ratio remained unchanged. Mean regional myocardial lactate extraction was not affected by sternotomy or halothane. During halothane administration one patient developed regional myocardial lactate production which was not present during sternotomy. However, another two patients, who had regional myocardial lactate production during sternotomy, did not produce lactate or had less negative value of regional myocardial lactate extraction during halothane administration.

Aged↗

The influence of right anterolateral thoracotomy in prepubescent female patients on late breast development and on the incidence of scoliosis.

BACKGROUND: It is assumed that a right anterolateral thoracotomy for correction of simple congenital cardiac defects (ie, atrial septal defect) achieves more favorable cosmetic results than a standard median sternotomy. METHODS: Ninety-five patients, 72 with right anterolateral thoracotomy and 23 with median sternotomy, who had corrective transatrial operations when they were younger than 12 years of age were contacted by questionnaire. The mean follow-up time was 23.1 years. Of these, 61 patients (46 thoracotomy and 15 sternotomy) were investigated clinically. Volume differences of the breasts were measured by 3-dimensional surface scanning. By using photographs of the upper chest, breast symmetry was described by an index. The degree of scoliosis was measured by clinical examination. RESULTS: According to the questionnaire analysis, 76% (thoracotomy group) versus 39% (sternotomy group) thought that the cosmetic result was excellent (P =.008). Breast volume measurement showed a volume difference greater than 20% (left side larger than right) in 55% (thoracotomy) versus 0% (sternotomy). With our index, asymmetry in the lower part of the right breast occurred in 61% (thoracotomy) versus 0% (sternotomy; P <.001). A total of 6.6% of the patients had scoliosis, without any differences between groups. CONCLUSIONS: Because our long-term follow-up in prepubescent female patients after right anterolateral thoracotomy revealed significantly impaired unilateral breast development, we propose to abandon right anterolateral thoracotomy in this subgroup of patients, although the subjective satisfaction with the cosmetic result was high. To avoid potential damage of future breast tissue, other surgical approaches, such as right posterior thoracotomy, should be considered. According to the orthopedic investigation, the surgical approach does not cause a higher rate of scoliosis.

Adult↗

Comparison of open and thoracoscopic bilateral volume reduction surgery: complications analysis.

BACKGROUND: The effectiveness of lung volume reduction for the treatment of patients with emphysema is well established, but data about the surgical approach, the postoperative management, and complications are limited. We report a comparison of patients undergoing bilateral lung volume reduction (BLVRS) via median sternotomy and thoracoscopic techniques with emphasis on hospital course and complications. METHODS: All patients undergoing BLVRS at Hospital of University of Pennsylvania were analyzed for mortality and morbidity, using a combination of prospective data analysis and retrospective chart review. RESULTS: Patients undergoing BLVRS via median sternotomy were older than those undergoing video-assisted thoracoscopic surgery (VATS) procedures (63.9+/-6.89 vs 59.3+/-9.4 years, p = 0.005). Operating time was longer for the VATS procedure (147 versus 129 minutes, p = 0.006) while estimated blood less was greater for median sternotomy (209 versus 82 L, p = 0.0000017). Significant differences were found in intensive care unit stay, days intubated, life-threatening complications, respiratory complications, requirement for tracheostomy, and death that favored VATS BLVRS. When only later cohorts of patients were compared, more life-threatening complications and deaths were found in patients undergoing BLVRS by median sternotomy. There were no differences between early and late median sternotomy BLVRS patients. Twenty-six percent of the lethal complications in median sternotomy BLVRS patients were bowel perforations, equally divided between duodenal ulcers and colons. CONCLUSIONS: Managing patients after BLVRS remains complex. Bilateral video-assisted volume reduction offers equivalent functional outcome with potentially decreased morbidity and mortality. Gastrointestinal perforations can complicate the management of these patients.

Blood Loss, Surgical↗

Minimally invasive or interventional repair of atrial septal defects in children: experience in 171 cases and comparison with conventional strategies.

OBJECTIVES: The goal of this study was to evaluate percutaneous interventional and minimally invasive surgical closure of secundum atrial septal defect (ASD) in children. BACKGROUND: Concern has surrounded abandoning conventional midline sternotomy in favor of the less invasive approaches pursuing a better cosmetic result and a more rational resource utilization. METHODS: A retrospective analysis was performed on the patients treated from June 1996 to December 1998. RESULTS: One hundred seventy-one children (median age 5.8 years, median weight 22.1 kg) underwent 52 device implants, 72 minimally invasive surgical operations and 50 conventional sternotomy operations. There were no deaths and no residual left to right shunt in any of the groups. The overall complication rate causing delayed discharge was 12.6% for minimally invasive surgery, 12.0% for midline sternotomy and 3.8% for transcatheter device closure (p < 0.01). The mean hospital stay was 2.8 +/- 1.0 days, 6.5 +/- 2.1 days and 2.1 +/- 0.5 days (p < 0.01); the skin-to-skin time was 196 +/- 43 min, 163 +/- 46 min and 118 +/- 58 min, respectively (p < 0.001). Extracorporeal circulation time was 49.9 +/- 10.1 min in the minithoracotomy group versus 37.2 +/- 13.8 min in the sternotomy group (p < 0.01) but without differences in aortic cross-clamping time. Sternotomy was the most expensive procedure (15,000 EUR +/- 1,050 EUR vs. 12,250 EUR +/- 472 EUR for minithoracotomy and 13,000 EUR +/- 300 EUR for percutaneous devices). CONCLUSIONS: While equally effective compared with sternotomy, the cosmetic and financial appeal of the percutaneous and minimally invasive approaches must be weighed against their greater exposure to technical pitfalls. Adequate training is needed if a strategy of surgical or percutaneous minimally invasive closure of ASD in children is planned in place of conventional surgery.

Analysis of Variance↗

Minimally invasive reoperative isolated valve surgery: early and mid-term results.

OBJECTIVE: Minimally invasive, nonsternotomy approaches for valve procedures may reduce the risks associated with cardiac surgery after prior sternotomy and may improve outcomes. We analyzed our institutional experience to test this hypothesis. METHODS: Between 1995 and 2002, 498 patients with previous cardiac operations via sternotomy underwent isolated valve surgery: 337 via median sternotomy (aortic = 160; mitral = 177) and 161 via mini-thoracotomy (aortic = 61; mitral = 100). Data were collected prospectively using the New York State Cardiac Surgery Report Form. RESULTS: Preoperative incidences of congestive heart failure, renal disease, and nonelective procedures were higher in the sternotomy group. Hospital mortality was significantly lower with the minimally invasive approach, 5.6% (9/161) versus 11.3% (38/337) (univariate, p = 0.04). However, multivariate analysis (odds ratio: 95% confidence intervals, p value) revealed that chronic obstructive pulmonary disease (6.6: 1.4 to 3.1, p = 0.001), renal disease (4.1: 1.52 to 11.2, p = 0.01), cerebrovascular disease (2.2: 1.03 to 4.78, p = 0.04), and ejection faction <30% (1.5: 0.96 to 5.5, p = 0.06) were associated with increased mortality. While mean bypass time, cross-clamp times, and stroke rates were comparable between groups, patients undergoing minimally invasive valve surgery had no deep wound infections (0% vs 2.4%, p = 0.05), less need for blood products (p = 0.02), and shorter hospital stays (p = 0.009). Five-year survival was higher with minimally invasive techniques as compared to a sternotomy approach (92.4 +/- 2% and 86.0 +/- 2%, respectively, p = 0.08). CONCLUSIONS: Reoperative valve surgery can be safely performed using a nonsternotomy, minimally invasive approach, with at least equal mortality, less hospital morbidity, decreased hospital length of stay, and slightly favorable mid-term survival as compared to sternotomy.

Adolescent↗

[Effects of R80122. The influence of a new phosphodiesterase inhibitor on global and intestinal hemodynamics in coronary surgery patients].

Phosphodiesterase III inhibitors have been established in recent years in the therapy of congestive heart failure. Many disadvantages, such as extensive vasodilation and the lack of proven positive inotropic properties combined with thrombepenia and elevation of transaminases, have complicated the handling of the drug in clinical practice. Enoximone, an imidazole derivative, has been demonstrated to be more cardioselective and vasodilation has been found to be less pronounced than with amrinone. As a consequence, research was performed to enhance the cardioselectivity of phosphodiesterase III inhibitors by reduction of non-specific cross-reactivity with other phosphodiesterases, and R80122 (Janssen Pharmaceutics, Belgium) was introduced into clinical practice. R80122 ((E)-Ncyclohexal-N-methyl-2[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1b]-quinazolin-7-yl)methylene] amino] oxy] acetamide) is a selective inhibitor of phosphodiesterase (PDE) IIIc, which is localized in the myocardium. Thus, its inhibition leads to a positive inotropic effect, whereas phosphodiesterase IIIRo is found in the vessel wall and causes vasodilation. This study was performed to investigate the hemodynamic profile of R80122 under clinical conditions. Additionally, the intestinal hemodynamics were recorded and changes in intestinal perfusion compared with changes in global hemodynamics. METHODS. The study was thoroughly discussed and approved by the local ethics committee; all patients gave written informed consent. The investigation was performed on ten male patients who were about to undergo elective coronary artery bypass surgery. History, physical examination and laboratory results were within the normal limits and revealed no evidence of liver disease. The usual medication was continued until the day before the operation. Premedication consisted of 2 mg flunitrazepam p.o. in the evening before the operation and 1.5 h before induction of anaesthesia. The determination of hepatic plasma flow was performed by the indocyanine green (ICG) infusion extraction technique using liver vein catheterization. After induction of anaesthesia (MP1), after application of a bolus dose of R80122 (0.3 mg/kg BW) (MP2) and at sternotomy (MP3), hemodynamic data (heart rate, arterial pressure, cardiac output) were recorded and blood samples for the determination of hepatic plasma flow by the concentration of ICG were collected. Anaesthesia was induced with a bolus dose of 0.2 mg/kg BW etomidate, 7 micrograms/kgBW fentanyl and 0.1 mg/kgBW pancuronium and maintained with a continuous infusion of 20 micrograms/min fentanyl, 300 micrograms/min midazolam and mechanical ventilation with O2/N2O at an FiO2 of 0.5. Statistical analysis was performed using the Wilcoxon-Mann-Whitney U test comparing the results after induction of anesthesia (MPI) with those after application of R80122 (MPII) and the results of MPII with those at sternotomy (MPIII). Statistical significance was assumed at P less than 0.05. RESULTS. After the induction of anaesthesia, the median heart rate (HR) was 56/min and did not change after administration of R80122. During sternotomy there was a significant increase in the HR from 64 to 78/min (P less than 0.05). Median arterial blood pressure (MAP) tended to decreased from 91 mm Hg after induction of 77 mm Hg after administration of R80122, although there was no statistical significance because of interindividual differences in the tendencies. At sternotomy, MAP remained unchanged. Cardiac output (CO) increased by 60% after administration of R80122 (P less than 0.01) and did not change during sternotomy. As a consequence of the changes in HR and CO, stroke volume (SV) increased by 22% after administration of R80122 (P less than 0.025) and decreased to control values during sternotomy.

Adult↗

[Coronary circulation, myocardial oxygen consumption and myocardial metabolism during enflurane-nitrous oxide anesthesia in coronary patients].

The effects of enflurane on myocardial oxygen consumption, metabolism and coronary blood flow (argon washin) were studied in 10 patients with 2- or 3-vessel coronary artery disease undergoing coronary artery bypass surgery. All patients were men with stable angina and normal left ventricular function and were on maintenance doses of beta-receptor- or calcium-antagonists. Anaesthesia consisted of enflurane and 50% nitrous oxide in oxygen. Measurements were performed and blood samples were taken with the patient awake, 30 min after induction of anaesthesia without any surgical stimulation and during sternotomy. End-tidal enflurane concentrations averaged 0.9% after induction and 2.5% during sternotomy. Enflurane decreased coronary blood flow significantly by 36% after induction, while sternotomy increased coronary blood flow by 29%. Myocardial oxygen uptake was decreased by 33% and was increased by 37% during sternotomy. Coronary vascular resistance did not change significantly during the entire observation period, while coronary sinus oxygen saturation significantly increased after induction by 20% followed by a decrease to preinduction levels during sternotomy. Myocardial glucose, free fatty acids, lactate and pyruvate uptake were significantly reduced after induction and increased to preinduction levels during sternotomy. Myocardial lactate production could not be demonstrated at any time during the observation period.

Anesthesia, Inhalation↗

Myocardial metabolism, catecholamine balance, and left ventricular function during coronary artery surgery: effects of nitroprusside and nifedipine.

The effects of nitroprusside and nifedipine on myocardial oxygen consumption (MVO2), catecholamine release, and left ventricular (LV) function (using 2D transesophageal echocardiography) were compared. Thirty-seven patients undergoing coronary artery surgery, anesthetized with fentanyl, 100 micrograms/kg, were studied. All had good LV function and had been receiving long-term oral beta-blocking therapy. Patients were randomly allocated to one of three groups. Group C (n = 12) received no vasodilator and served as control. Group S (n = 13) received nitroprusside at an initial rate of 1 microgram/kg/min. Group N (n = 12) received nifedipine at an initial rate of 0.7 microgram/kg/min. Baseline measurements were obtained ten minutes after intubation. Vasodilator therapy was then started in groups S and N. Infusion rates were adjusted to maintain systolic blood pressure (SBP) between 80% and 120% of baseline values. Additional measurements were made ten minutes after the start of the infusion, ie, before surgery (in group C immediately before surgery), and after sternotomy when the pericardium was opened. The mean (+/- SD) total dose requirements were 1.9 +/- 0.5 micrograms/kg/min for nitroprusside and 1.1 +/- 0.2 micrograms/kg/min for nifedipine. The mean (+/- SD) total infusion time was 31 +/- 5 minutes for nitroprusside and 32 +/- 11 minutes for nifedipine. After sternotomy, heart rate increased in all groups. At this time arterial blood pressure and systemic vascular resistance (SVR) increased in group C. SVR was decreased after the first ten minutes of nitroprusside infusion and after sternotomy in group S. Coronary sinus blood flow, MVO2, and myocardial norepinephrine release increased in group N, but not in groups C or S. After sternotomy, LV percentage area reduction increased in groups S and N, but not in group C. In group N there was a significant correlation (r = 0.65; P less than .05) between the increases in MVO2 and LV percentage area reduction, an estimate of myocardial function. Lactate production occurred in two patients in group C after sternotomy. This was not associated with ECG changes, but in one patient regional wall motion abnormalities developed. No evidence of myocardial ischemia was observed in groups S and N. However, in contrast to nitroprusside, the use of nifedipine was associated with increases in MVO2, myocardial norepinephrine release, and inotropy.

Blood Pressure↗

Is the femoral cannulation for minimally invasive aortic valve replacement necessary?

INTRODUCTION: Minimally invasive cardiac surgery through a small transverse sternotomy is a new promising technique that can be considered an alternative in most cases to aortic valve replacement thus reducing surgical trauma and subsequent time of hospitalization. The need to avoid the risks associated with femoro-femoral bypass has lead to the interest in aortic valve replacement (AVR) operations without femoral vessels cannulation. We want to emphasize a few important points of our technique, which differs somewhat from the one applied by Cosgrove and associates. OBJECTIVE: This study details the approach to the minimally invasive AVR as first described by. Cosgrove et al. without standard femoral cannulation and points out our preliminary clinical experience. PATIENTS AND METHODS: From October 1996 to May 1997 we have operated on 25 patients using minimally invasive AVR (MI-AVR) In 23 cases, access through transverse sternotomy as described by Cosgrove et al., was performed. In two additional cases the chest is opened via a mini-median sternotomy with an 'L'-shape extending from the sternal notch to the superior edge of the third interspace. Twenty-three patients underwent AVR through transverse sternotomy. The male/female ratio was 13:10. The mean age was 67 years (range 45-78 years). Seventy-four percent of the patients were over 65. Predominantly, in 43% of cases aortic valve stenosis and in 25% of cases aortic valve regurgitation isolated is presented. In 19 cases, a 10-cm transverse incision is performed over the second interspace. Likewise, in four cases over the third interspace according to the thorax morphology and length of the ascending aorta assessed by chest X-ray films. By convention, cannulation of the ascending aorta and right atrial appendage was performed as usual. In contrast, in one patient (5.5%), cannulation was placed in the superior vena cava and right common femoral vein into the inferior vena cava. In the present series, 15 mechanical prostheses and eight bioprostheses whose used sizes were 19, 21,23, and 25 mm in diameter were placed in four, nine, nine, and one of the cases, respectively. All patients underwent AVR electively and a transesophageal echocardiography probe is made. RESULTS: During surgery, conversion to median sternotomy was not required in any patient. Mean aortic cross-clamp time was 68 min (range 38-90 min). Mean total bypass time was 87 min (range 50-120 min). Mean postoperative bleeding was 434 ml. (range 200-850 ml). Perioperative blood transfusion was required in 17% of the patients. Mean mechanical ventilation time was 7.3 h (range 3-24 h), with a mean ICU stay of 18 h. Mean postoperative hospital stay was 4.5 days (range 3-10 days). In all cases, transthoracic and transesophageal echocardiography were performed postoperatively Prosthetic valve dysfunction was not observed. On the other hand, just one patient (4%) died 5 days after operation due to sudden cardiac death. Further, in two patients (8%), during follow-up, pericardial effusion is detected. In one case, cardiac tamponade with hemodynamic instability required a pericardial window procedure. In addition, in two patients (8%), non-infectious sternal dehiscence required reinforced sternal closure. CONCLUSIONS: Minimally invasive AVR surgery without femoral vessel cannulation is a safe procedure with less surgical aggression. After a learning curve, benefits on fast-track programs will be accomplished.

Aged↗