Giovanni Carboni

Surgical Reexploration After Cardiac Operations: Why a Worse Outcome?

BACKGROUND Surgical reexploration due to postoperative bleeding occurs in 2% to 6% of cardiac surgical patients and is accompanied by increased morbidity and mortality. In this study, we addressed the postoperative course of patients needing surgical reexploration, with specific respect to the timing of reexploration and the transfusional needs as determinants of morbidity and mortality. METHODS This was a retrospective study of 232 patients having undergone surgical reexploration owing to postoperative bleeding after cardiac operations, compared with a control, propensity-matched group. RESULTS Patients in the surgical reexploration group had greater morbidity (low cardiac output, acute renal failure, sepsis) and longer mechanical ventilation time and intensive care unit stay than did control patients, and a significantly higher mortality rate (14.2% versus 3.4%, p = 0.001). The timing of surgical reexploration was not associated with morbidity or mortality. The amount of packed red cells transfused was significantly associated with increased morbidity (acute renal failure, low cardiac output syndrome, sepsis), with mechanical ventilation time and intensive care unit stay, and with the mortality rate (0.25% increase for each unit transfused). CONCLUSIONS The main determinant of morbidity and mortality for patients requiring a surgical reexploration after cardiac operations is the amount of packed red cells transfused. Delaying the timing of reexploration may represent a risk factor only when the delay creates the need for an excessive use of allogeneic blood products, or in the presence of clinical signs of cardiac tamponade.

Acute Kidney Injury and Hemodilution During Cardiopulmonary Bypass: A Changing Scenario

BACKGROUND Severe hemodilution during cardiopulmonary bypass (CPB) is a risk factor for acute kidney injury (AKI) after heart operations. Many improvements to CPB technology have been proposed during the past decade to limit the hemodilution-related AKI risk. The present study is a retrospective analysis of the relationship between hemodilution during CPB and AKI in cardiac operations in the setting of different interventions applied over 14 years. METHODS We retrospectively analyzed 16,790 consecutive patients undergoing heart operations from 2000 to 2013. Various risk factors for AKI were collected and analyzed, together with a number of interventions as possible modifiers of the relationship between a nadir hematocrit (HCT) value during CPB and AKI. RESULTS The relationship between the nadir HCT value during CPB and AKI was confirmed in a multivariable analysis, with the relative risk of AKI increasing by 7% per percentage point of decrease of the nadir HCT value during CPB. The relative risk of AKI decreased by 8% per year of observation (p = 0.001) despite a significantly increased risk of AKI (p = 0.001). A sensitivity analysis based on differences before and after different interventions demonstrated a beneficial effect of the application of goal-directed perfusion (aimed at preserving oxygen delivery during CPB), with a reduction in the AKI rate from 5.8% to 3.1% (p = 0.001). A policy restricting angiographic examination on the day of operation was also useful (reduction of AKI rate from 4.8% to 3.7%; p = 0.029). CONCLUSIONS A bundle of interventions mainly aimed at limiting the renal impact of hemodilution during CPB is effective in reducing the AKI rate.

Inhibition of tissue transglutaminase sensitizes TRAIL-resistant lung cancer cells through upregulation of death receptor 5

Tissue transglutaminase (TG2) is implicated in cellular processes such as apoptosis and cell migration. Its acyl transferase activity cross‐links certain proteins, among them transcription factors were described. We show here that the TG2 inhibitor KCC009 reversed resistance to tumor necrosis factor‐related apoptosis‐inducing factor (TRAIL) in lung cancer cells. Sensitization required upregulation of death receptor 5 (DR5) but not of death receptor 4. Upregulation of DR5 involved the first intron of the DR5 gene albeit it was independent from p53 and nuclear factor kappa B. In conclusion, inhibition of tissue transglutaminase provides an interesting strategy for sensitization to TRAIL‐induced apoptosis in p53‐deficient lung cancer cells.

Comparison of procalcitonin and CrP in the postoperative course after lung decortication

OBJECTIVE The objective of this prospective study was to compare the clinical value of procalcitonin (PCT) and C-reactive protein (CrP) plasma concentrations in their postoperative course after decortication. METHODS Twenty-two patients requiring surgery for pleural empyema were chosen for this prospective study. Routine blood samples including CrP and PCT plasma concentrations were taken before the operation and on the 1st, 2nd, 3rd, and 7th postoperative day. RESULTS Due to infection PCT and CrP were elevated preoperatively. In the postoperative course both PCT and CrP reached peak-levels on day 2 with values up to 43.55 ng/ml and 384.00 mg/l, respectively. In PCT the rise was followed by a clear decrease in 20 (90.9 %) patients until day 7. In contrast the CrP levels decreased slowly and only seven (54.5%) patients had values of 100 mg/l or below on day 7. PCT showed a better correlation with the clinic in case of septic course than CrP does. CONCLUSIONS PCT reflects postoperative clinical course more accurately than CrP. Therefore, PCT is a more appropriate laboratory parameter to monitor patients after surgery for pleural empyema.

Survival and graft function in a large animal lung transplant model after 30 h preservation and substitution of the nitric oxide pathway.

OBJECTIVE Substitution of the nitric oxide- (NO-) pathway improves early graft function following lung transplantation. We previously demonstrated that 8-Br-cGMP (second messenger of NO) to the flush solution and tetrahydrobiopterin (BH4, coenzyme of NO synthase) given as additive during reperfusion improve post-transplant graft function. In the present study, the combined treatment with 8-Br-cGMP and BH4 was evaluated. METHODS Unilateral left lung transplantation was performed in weight matched outbred pigs (24-31 kg). In group I, grafts were preserved for 30 h (n=5). 8-Br-cGMP (1mg/kg) was added to the flush solution (Perfadex, 1.5l, 1 degrees C) and BH4 (10mg/kg/h) was given to the recipient for 5h after reperfusion. In group II, lungs were transplanted after a preservation time of 30 h (n=3) and prostaglandin E(1) (250 g) was given into the pulmonary artery (PA) prior to flush. In all recipients 1h after reperfusion the contralateral right PA and bronchus were ligated to assess graft function only. Survival time after reperfusion, extravascular lung water index (EVLWI), hemodynamic variables, and gas exchange (PaO(2)) were assessed during a 12h observation period. RESULTS All recipients in group I survived the 12h assessment, whereas none of the group II animals survived more than 4h after reperfusion with a rapid increase of EVLWI up to 24.8+/-6.7 ml/kg. In contrast, in group I EVLWI reached up to 8.9+/-1.5 ml/kg and returned to nearly normal levels at 12h (6.1+/-0.8 ml/kg). In two animals of group I the gas exchange deteriorated slightly. The other three animals showed normal arterial oxygenation over the entire observation time. CONCLUSION Our data indicate that the combined substitution of the NO pathway during preservation and reperfusion reduces ischemia/reperfusion injury substantially and that this treatment even allows lung transplantation after 30 h preservation in this model.

Cardiac catheterization and postoperative acute kidney failure in congenital heart pediatric patients

BACKGROUND: Acute renal failure (ARF) is a severe complication of cardiac operations in pediatric patients. Angiography with the exposure to contrast media is a risk factor for ARF. In the present study, we explored the association between timing of angiography, dose of contrast media, and the incidence of ARF after cardiac operations in pediatric patients. METHODS: We performed a retrospective analysis of prospectively collected data. Angiographic data and other covariates were collected in 277 patients aged ⩽12 years receiving angiography and cardiac operations during the same hospital stay. Renal outcome was assessed according to the pediatric Risk, Injury, Failure, Loss of function, End stage score (pRIFLE). RESULTS: One hundred seventy-seven (64%) patients suffered some degree of postoperative renal dysfunction, and 55 (20%) had ARF (pRIFLE stage Failure). Patients with ARF received a significantly (P < 0.001) larger dose of iodine contrast media (4.6 ± 2.6 g/kg) with respect to the other patients (2.8 ± 2.2 g/kg), with a relative risk increase for ARF of 31% per each incremental iodine dose of 1 g/kg at the univariate analysis. A multivariable risk model demonstrated that the risk for ARF is 20 times higher in patients aged younger than 2 years and 3 times higher in case of postoperative low cardiac output. Within this model, the iodine dose on angiography is confirmed as an independent risk factor for ARF, with a relative risk increase for ARF of 16% per each incremental iodine dose of 1 g/kg. CONCLUSIONS: Angiography before cardiac surgery is an important risk factor for ARF in pediatric patients. Being a modifiable risk factor, the contrast media dose should be limited to the lowest possible value, avoiding large doses of iodine which, together with other factors (age and postoperative low cardiac output), concur in the determinism of postoperative ARF.

Hemodilution on Cardiopulmonary Bypass as a Determinant of Early Postoperative Hyperlactatemia

Objective The nadir hematocrit (HCT) on cardiopulmonary bypass (CPB) is a recognized independent risk factor for major morbidity and mortality in cardiac surgery. The main interpretation is that low levels of HCT on CPB result in a poor oxygen delivery and dysoxia of end organs. Hyperlactatemia (HL) is a marker of dysoxic metabolism, and is associated with bad outcomes in cardiac surgery. This study explores the relationship between nadir HCT on CPB and early postoperative HL. Design Retrospective study on 3,851 consecutive patients. Measurements and Main Results Nadir HCT on CPB and other potential confounders were explored for association with blood lactate levels at the arrival in the Intensive Care Unit (ICU), and with the presence of moderate (2.1 – 6.0 mMol/L) or severe (> 6.0 mMol/L) HL. Nadir HCT on CPB demonstrated a significant negative association with blood lactate levels at the arrival in the ICU. After adjustment for the other confounders, the nadir HCT on CPB remained independently associated with moderate (odds ratio 0.96, 95% confidence interval 0.94-0.99) and severe HL (odds ratio 0.91, 95% confidence interval 0.86-0.97). Moderate and severe HL were significantly associated with increased morbidity and mortality. Conclusions Hemodilution on CPB is an independent determinant of HL. This association, more evident for severe HL, strengthens the hypothesis that a poor oxygen delivery on CPB with consequent organ ischemia is the mechanism leading to hemodilution-associated bad outcomes.

Heparin-like effect in postcardiotomy extracorporeal membrane oxygenation patients

IntroductionUnfractionated heparin (UFH) is the anticoagulant of choice for extracorporeal membrane oxygenation (ECMO), but bivalirudin can be used as an alternative. The purpose of the present study is to investigate the existence of a heparin-like effect (HLE) during heparin-free ECMO.MethodsThis is a retrospective study on patients treated with ECMO and receiving bivalirudin as the sole anticoagulant. Thromboelastography (TEG) tests with and without heparinase were recorded during the ECMO duration. A total of 41 patients (22 pediatrics and 19 adults) treated with ECMO after cardiac surgery procedures and receiving only bivalirudin-based anticoagulation were studied. Based on the presence of a different reaction time (R-time) between the TEG test with heparinase or without heparinase we defined the presence of a HLE. Survival to hospital discharge, liver failure, sepsis, bleeding and transfusion rate were analyzed for association with HLE with univariate tests.ResultsHLE was detected in 56.1% of the patients. R-times were significantly shorter in tests done with heparinase versus without heparinase during the first seven days on ECMO. Patients with HLE had a significantly (P = 0.046) higher rate of sepsis (30%) than patients without HLE (5.6%) at a Pearsons chi-square test.ConclusionsA heparin-like effect is common during ECMO, and most likely due to a release of heparinoids from the glycocalyx and the mast cells, as a consequence of sepsis or of the systemic inflammatory reaction triggered by the contact of blood with foreign surfaces.

The role of muscle flap in preventing bronchus stump insufficiency after pneumonectomy for malignant pleural mesothelioma in high-risk patients.

Bronchus stump insufficiency (BSI) is one of the major complications after pneumonectomy; we analyzed all patients who underwent extra pleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM) in order to detect the role of muscle flap (MF) on preventing early and late stump insufficiency. From January 2000 until December 2005, there were 42 patients admitted with MPM for further intervention at our institution. Thirty patients were suitable for surgery and thus received a multimodal treatment with neo-adjuvant chemotherapy using Cisplatin and Gemcitabin (Gemzar), EPP followed by 54 Gray (Gy) adjuvant radiotherapy. Data were collected from the surgical and oncological records. There were 37 male patients (88%), the median age was 65 years (range 40-83 years). Seven (17%) patients had concomitant diseases. Forty patients (95%) had asbestos exposition. The operative procedures were EPP with muscle flap through an anterolateral thoracotomy. Univariate and multivariate analyses were done. One patient (3%) died on the 2nd postoperative day due to lung embolism. Mild complications were noticed in the early postoperative phase in 8 (25%) patients. There was no early or late stump insufficiency during the 15-month follow-up. Surgical techniques using muscle flap seems to play a major role in the prevention of bronchus stump insufficiency especially after neo-adjuvant chemotherapy.

Video thoracoscopic surgery used to manage tuberculosis in thoracic surgery

BackgroundThe aim of this study was to evaluate the indications and results of video-assisted thoracic surgery (VATS) for the management of tuberculosis in 10 patients with unusual clinical and radiologic presentation for the disease.MethodsFrom March 2000 to March 2002, 96 diagnostic VATS operations for unclear thoracic lesions were performed at the authors’ institution. Their final diagnosis for 10 (10.4%) of these patients was tuberculosis. The suspected preoperative diagnoses were pancoast tumour (n = 1), pericardial effusion (n = 1), pleural mesothelioma (n = 1), pleural empyema (n = 2), mediastinal lymphoma (n = l), and lung cancer (n = 4).ResultsFor all the patients, the diagnosis of tuberculosis was achieved by VATS. The duration of drainage was 2.5 days. There have been neither morbidity nor mortality since surgery. The hospital stay was 3 to 5 days.ConclusionThoracoscopy is a safe and effective procedure for the management of tuberculosis. Tuberculosis should be kept in mind during the differential diagnosis of unknown thoracic lesions, and also for patients who live in economically well developed countries and are not immune compromised.