Minimally Invasive Aortic Valve Surgery in Octogenarians: Reliable Option or Fallback Solution?

OBJECTIVE: Aortic valve disease is more and more common in western countries. While percutaneous approaches should be preferred in older adults, previous reports have shown good outcomes after surgery. Moreover, advantages of minimally invasive approaches may be valuable for octogenarians. We sought to compare outcomes of conventional aortic valve replacement (CAVR) versus minimally invasive aortic valve replacement (MIAVR) in octogenarians. METHODS: We retrospectively collected data of 75 consecutive octogenarians who underwent primary, elective, isolated aortic valve surgery through conventional approach (41 patients, group CAVR) or partial upper sternotomy (34 patients, group MIAVR). RESULTS: Mean age was 81.9 ± 0.9 and 82.3 ± 1.1 years in CAVR and MIAVR patients, respectively (P = 0.09). MIAVR patients had lower 24-hour chest drain output (353.4 ± 207.1 vs 501.7 ± 229.9 mL, P < 0.01), shorter mechanical ventilation (9.6 ± 2.4 vs 11.3 ± 2.3 hours, P < 0.01), lower need for blood transfusions (35.3% vs 63.4%, P = 0.02), and shorter hospital stay (6.8 ± 1.6 vs 8.3 ± 4.3 days, P < 0.01). Thirty-day mortality was zero in both groups. Survival at 1, 3, and 5 years was 89.9%, 80%, and 47%, respectively, in the CAVR group, and 93.2%, 82.4%, and 61.8% in the MIAVR group, with no statistically significant differences (log-rank test, P = 0.35). CONCLUSIONS: Aortic valve surgery in older patients provided excellent results, as long as appropriate candidates were selected. MIAVR was associated with shorter mechanical ventilation, reduced blood transfusions, and reduced hospitalization length, without affecting perioperative complications or mid-term survival.

Is the pCO2 gap obtained from the superior vena cava in agreement with that from the pulmonary artery?

BACKGROUND: The partial pressure of carbon dioxide (pCO2) gap is the difference between pCO2 values in the arterial and mixed venous blood; values higher than six mmHg may be predictive of tissue hypoperfusion. It is still doubtful if central venous blood can be used to assess the gap. This study was aimed to compare the values obtained with blood collected from the superior vena cava and the pulmonary artery. METHODS: Data were obtained from a previous study. In 30 patients who underwent on-pump myocardial revascularization, blood samples from a radial artery, the pulmonary artery, and the superior vena cava were collected eight times in the perioperative period. Two-hundred determinations were utilized to calculate the pCO2 gap from central and mixed venous pCO2. RESULTS: The pCO2 gap was 8.7±2.6 mmHg in the superior vena cava, and 6.0±2.7 in the pulmonary artery. The difference between the two values fell within a wide interval between -4.1 mmHg and +9.5 mmHg in 95% of cases. pCO2 values were significantly higher in the superior vena cava than in the pulmonary artery (mean difference 2.7±2.4 mmHg; P<0.0001), causing a systematic bias between the two estimates; such bias increased during spontaneous breathing (P=0.0249). CONCLUSIONS: pCO2 values are higher in the superior vena cava than in the pulmonary artery. As a consequence, the pCO2 gap calculated with the blood taken from the superior vena cava is overestimated, probably because it reflects the pCO2 arteriovenous difference of the upper part of the body, in particular of the brain.

Dynamic right ventricular outflow obstruction: A rare cause of hypotension during anestesia induction.

INTRODUCTION: Dynamic obstruction of right ventricle outflow tract (RVOTO) is a rare condition that may acutely cause severe heart failure. It has been reported in some hypertrophic cardiomyopathies, after lung transplantation, and in some cases of hemodynamic instability after cardiopulmonary bypass. PRESENTATION OF CASE: We report the case of a 71-year-old man who developed severe hypotension during the induction of general anesthesia for surgical coronary revascularization. Hypotension did not respond to the initial treatment with vasoconstrictors and fluids. RVOTO was suspected during pulmonary artery catheterization because of the difficulty of the catheter tip to move from the right ventricle to the pulmonary artery and, successively, because of the finding of a large gradient between the systolic pressure in the right ventricle and in the pulmonary artery. The diagnosis was confirmed by transesophageal echocardiogram (TEE). Hemodynamics recovered after the infusion of cristalloids, 1L, and the suspension of vasoconstrictors and inotropes. DISCUSSION: This is the first case in which RVOTO was observed during the induction of general anesthesia. Although this is a rare condition, the diagnostic suspect is of outmost importance because treatment is mainly based on fluid administration, and drugs with positive inotropic properties (like most vasoconstrictors) are contraindicated. CONCLUSIONS: RVOTO is an unusual, but possible cause of severe arterial hypotension during general anesthesia induction. TEE is useful for the evaluation of severely hypotensive patients who do not respond to routine treatment with fluids and vasoconstrictors.

Managing latex-free mitral valve replacement.

The management of cardiac surgery patients with latex allergy can be challenging. We describe successful mitral valve replacement in a latex-allergic patient using an integrated multidisciplinary approach. We also provide a list of some available latex-free products or latex-free alternatives.

Cardiopulmonary bypass in man: role of the intestine in a self-limiting inflammatory response with demonstrable bacterial translocation.

BACKGROUND: Cardiopulmonary bypass provokes a systemic inflammatory reaction that, in 1% to 2% of all cases, leads to multiorgan disfunction. The aim of this study was to evaluate the possible role of the intestine in the pathogenesis and development of this reaction. METHODS: Eleven selected patients scheduled for elective coronary artery bypass graft surgery were enrolled in a open, prospective clinical study. Gastric tonometry, chromium-labeled test and double sugar intestinal absorption tests, polymerase chain reaction microbial DNA test, and measurement of cytokines and transcriptional factor (nuclear factor kappaB) activation were performed. RESULTS: During the postoperative period, gastric pH remained stable (range,7.2 to 7.3). The partial pressure for carbon dioxide gradient between the gastric mucosa and arterial blood increased significantly (from 1 to 23 mm Hg), peaking in the sixth postoperative hour. Interleukin 6 increased significantly over basal levels, peaking 3 hours after cardiopulmonary bypass (96.3 versus 24 pg/mL). Nuclear factor kappaB never reached levels higher than those observed after lipopolysaccharide stimulation. Escherichia coli translocation was documented in 10 patients: in eight cases from removal of aortic cross-clamps and in two cases from the first postoperative hour. With respect to basal value (6.4%), the urine collection revealed a significant increase in excretion of the radioisotope during the first 24 hours after surgery (39.1%), although there were no significant variations with the double sugar test. CONCLUSIONS: The results obtained showed a correlation between the damage of the gastrointestinal mucosa, subsequent increased permeability, E coli bacteremia, and the activation of a self-limited inflammatory response in the absence of significant macrocirculatory changes and postoperative complications.