José Luis Aranda

Predicting pulmonary complications after pneumonectomy for lung cancer

OBJECTIVES Patients undergoing pneumonectomy for lung cancer are thought to be at high risk for the development of postoperative pulmonary complications (PC) and these complications are associated with high mortality rates. The purpose of this study was to identify independent factors associated with increased risk for the development of postoperative PC after pneumonectomy for lung cancer, and to assess the usefulness of predicted pulmonary function to identify high risk patients and other adverse outcomes. PATIENTS AND METHODS We reviewed retrospectively 242 patients undergoing pneumonectomy for lung cancer during a 12-year period. Perioperative data (clinical, pulmonary function test, and surgical) were recorded to identify risk factors of PC by univariate and multivariate analyses. RESULTS Overall mortality and morbidity rates were 5.4 and 59%, respectively. Thirty-four patients (14%) developed PC (acute respiratory failure, ARF = 8.7%, reintubation = 5.4%, pneumonia = 3.3%, atelectasis = 2.9%, postpneumonectomy pulmonary edema = 2.5%, mechanical ventilation more than 24 h = 1.2%, pneumothorax = 0.8%). Patients with surgical (P < 0.001), cardiac (P < 0.001) and other complications (P < 0.01) had higher incidence of PC than those without postoperative complications. Intensive care unit stay (53 +/- 39 h vs. 35 +/- 19 h; P < 0.001) and hospital stay (18 +/- 11 days vs. 12 +/- 7 days; P < 0.001) was significantly longer in patients with PC. The mortality rate associated with PC was 35.5% (P < 0.001). By univariate analysis, it was found that older patients (P = 0.007), chronic obstructive pulmonary disease (COPD) (P = 0.023), heart disease (P = 0.019), no previous record of chest physiotherapy (P = 0.008), poor predicted postoperative forced expiratory volume in 1s (ppo-FEV1) (P = 0.001), and prolonged anesthetic time (P < 0.001) were related with higher risk of PC. In the multiple logistic regression model, the anesthetic time (minutes; odds ratio, OR = 1.012), ppo-FEV1 (ml/s; OR = 0.998), heart disease (OR = 2.703), no previous record of previous chest physiotherapy (OR = 2.639), and COPD (OR = 2.277) were independent risk factors of PC. CONCLUSIONS PC after pneumonectomy are associated with high mortality rates. Careful attention must be paid to patients with COPD and heart disease. Our results confirm the relevance of previous chest physiotherapy and the importance of the length of the surgical procedure to minimize the incidence of PC. The predicted pulmonary function (ppo-FEV1) may be useful to identify high risk patients for PC development and adverse outcomes.

Prediction of early bronchopleural fistula after pneumonectomy: a multivariate analysis

BACKGROUND The aim of this study was to determine independent risk factors for early bronchopleural fistula (BPF) after pneumonectomy and to assess the efficacy of bronchial coverage in preventing this complication. METHODS We reviewed 242 consecutive patients undergoing pneumonectomy for lung cancer. The bronchial stump was covered with autologous tissue in 178 patients (74%). Perioperative data were recorded to identify risk factors of BPF by univariate and multivariate analyses. RESULTS Overall morbidity and mortality rates were 59% and 5.4%, respectively. The incidence of BPF was 5.4%. By univariate analysis, patients with chronic obstructive pulmonary disease (COPD; p = 0.017), hyperglycemia (p = 0.003), hypoalbuminemia (p = 0.017), previous steroid therapy (p < 0.001), poor predicted postpneumonectomy forced expiratory volume in 1 second (FEV1; p = 0.012), long bronchial stumps (p < 0.001), and mechanical ventilation (p = 0.015), were related with higher risk of BPF. In the multiple logistic regression model, the independent risk factors of BPF were the bronchial stump coverage and length, side of pneumonectomy, predicted postpneumonectomy FEV1, COPD, and mechanical ventilation. CONCLUSIONS Bronchial stump coverage is highly recommended in all cases to minimize the risks of BPF. A shorter length of the bronchial stump and early extubation may prevent the development of BPF. Careful attention must be paid to those patients with COPD and poor predicted postpneumonectomy FEV1.

Postoperative chest tube management: measuring air leak using an electronic device decreases variability in the clinical practice

OBJECTIVES Since there are no data in the literature regarding variability in the management of postoperative pleural drainages, we have designed a prospective randomized study aimed at measuring inter-observer variability in deciding when to withdraw chest tubes after lung resection and to evaluate if the use of an electronic device to measure postoperative air leak decreases clinical practice variations. METHODS Sixty-one patients undergoing pulmonary resection were randomly assigned to one of the following groups: digital group (electronic measure of pleural air leak using Millicore AB DigiVent chest drainage system) or traditional group (standard water seal pleural chamber). Chest tube withdrawal criteria were established in advance. During morning rounds, two thoracic surgeons with comparable clinical experience and blinded to the decision of their counterpart, evaluated chest tube withdrawal criteria and noted whether the tube should be withdrawn or not. Inter-observer variability kappa index and global, positive, and negative agreement rates were calculated on 2 x 2 tables. Each observation episode was considered in the calculation. RESULTS Fifty-four observations were recorded in the traditional group. Kappa coefficient was 0.37 (overall agreement rate: 0.58; positive agreement rate: 0.72; and negative agreement rate: 0.64). In the digital group, 67 observations were recorded. Kappa coefficient was 0.88 (overall agreement rate: 0.94; positive agreement rate 0.94; and negative agreement rate 0.94). CONCLUSIONS We have demonstrated a high rate of disagreement related to the indication to remove chest tubes after lung resection and the improvement of the agreement rate with the use of an electronic device to measure postoperative air leak and pleural pressures.

A Scoring System to Predict the Risk of Prolonged Air Leak After Lobectomy

BACKGROUND Prolonged air leak (PAL) remains a frequent complication after lung resection. Perioperative preventative strategies have been tested, but their efficacy is often difficult to interpret due to heterogeneous inclusion criteria. The objective of this study was to develop and validate a practical score to stratify the risk of PAL after lobectomy. METHODS Six hundred fifty-eight consecutive patients were submitted to pulmonary lobectomy (2000 to 2008) in center A and were used to develop the risk-adjusted score predicting the incidence of PAL (> 5 days). Exclusion criteria were chest wall resection and postoperative assisted mechanical ventilation. No sealants, pleural tent, or buttressing material were used. To build the aggregate score numeric variables were categorized by receiver operating curve analysis. Variables were screened by univariate analysis and then used in stepwise logistic regression analysis (validated by bootstrap). The scoring system was developed by proportional weighing of the significant predictor estimates and was validated on patients operated on in a different center (center B). RESULTS The incidence of PAL in the derivation set was 13% (87 of 658 cases). Predictive variables and their scores were the following: age greater than 65 years (1 point); presence of pleural adhesions (1 point); forced expiratory volume in one second less than 80% (1.5 points); and body mass index less than 25.5 kg/m(2) (2 points). Patients were grouped into 4 risk classes according to their aggregate scores, which were significantly associated with incremental risk of PAL in the validation set of 233 patients. CONCLUSIONS The developed scoring system reliably predicts incremental risk of PAL after pulmonary lobectomy. Its use may help in identifying those high-risk patients in whom to adopt intraoperative prophylactic strategies; in developing inclusion criteria for future randomized clinical trials on new technologies aimed at reducing or preventing air leak; and for patient counseling.

Influence of major pulmonary resection on postoperative daily ambulatory activity of the patients

To describe and compare the daily ambulatory activity of the patients before and one month after major lung resection. Daily activity was measured using a pedometer (OMROM Walking Style PRO) given preoperatively in a prospective way to a series of 21 consecutive cases scheduled for lobectomy or pneumonectomy. Analyzed variables were age, pulmonary function, mean number of total and aerobic steps per day, walked distance and mean daily time of aerobic activity. Activity variables were analyzed individually and as a new differential variable DELTA. Wilcoxon and Mann-Whitney nonparametric tests were used for comparison between groups. General series data: 19 male. Age: 63+/-10.9 years. FEV(1)%: 88.4+/-22.7. DLCO: 86.2+/-21.6. Eleven cases had COPD criteria. Type of surgery: 3 pneumonectomy/18 lobectomy. Activity data: all patients showed a global decrease of their activity one month after surgery but, patients in the pneumonectomy group are unable to keep aerobic activity meanwhile patients that undergone lobectomy showed only a 25% reduction in the measured variables. Major pulmonary resection decreases the time and the quality of the daily ambulatory activity of the patients during the first postoperative month. Despite limitations, the chosen pedometer OMRON Walking Style Pro is an efficient tool to evaluate the perioperative daily ambulatory activity of patients.

Tridimensional titanium-printed custom-made prosthesis for sternocostal reconstruction

A broad range of materials have been described for sternal reconstruction in order to guarantee not only the best preservation of respiratory mechanics, but also adequate mediastinal protection and acceptable cosmetic results. Today, titanium implants are preferred by many surgeons because of their optimal features. As a step forward, tridimensional (3D) laser sintering printing techniques allow us to virtually reproduce even more complex bony structures. Here, we present a case of sternocostal reconstruction by means of a 3D titanium-printed custom-made prosthesis after extensive resection of a chest wall sarcoma. The use of an intraoperative template to precisely set resection margins, the novel prosthetic design as well as a new and safer rib fixation system may offer some advantages over other custom-made reconstructive techniques.

Autologous fibrin scaffolds cultured dermal fibroblasts and enriched with encapsulated bFGF for tissue engineering

Autologous fibrin scaffolds (AFSs) enriched with cells and specific growth factors represent a promising biocompatible scaffold for tissue engineering. Here, we analyzed the in vitro behavior of dermal fibroblasts (DFs) (cellular attachment, distribution, viability and proliferation, histological and immunohistochemical changes), comparing AFS with and without alginate microcapsules loaded with basic fibroblast growth factor (bFGF), to validate our scaffold in a future animal model in vivo. In all cases, DFs showed good adhesion and normal distribution, while in scaffolds with bFGF at 14 days, the cell counts detected in proliferation and viability assays were greatly improved, as was the proliferative state, and there was a decrease in muscle specific actin expression and collagen synthesis in comparison with the scaffolds without bFGF. In addition, the use of plasma without fibrinogen concentration methods, together with the maximum controlled release of bFGF at 14 days, favored cell proliferation. To conclude, we have been able to create an AFS enriched with fully functional DFs and release-controlled bFGF that could be used in multiple applications for tissue engineering.

The risk of death due to cardiorespiratory causes increases with time after right pneumonectomy: a propensity score-matched analysis †

OBJECTIVES The study aimed to compare in-hospital, 30-day and non-cancer-related 6-month death rates in a series of right and left pneumonectomy cases matched according to functional parameters. METHODS A retrospective study was conducted on a series of 263 non-small cell lung cancer patients who underwent pneumonectomy. Left and right pneumonectomy cases were matched according to propensity scores using the following variables: age, coronary artery disease, any other cardiac comorbidity and predicted postoperative forced expiratory volume in the 1st second (ppoFEV1). After matching, 89 pairs of cases were selected. In-hospital, 30-day and 6-month crude and risk-adjusted death rates not related to cancer relapse or distant metastases were calculated for right and left pneumonectomy and compared on 2-by-2 tables using odds ratios. Death hazards were estimated by Cox regression, introducing the following independent variables in the model: age, cardiac comorbidity, ppoFEV1 and occurrence of any postoperative cardiorespiratory complication or bronchial fistula. RESULTS Non-cancer-related in-hospital, 30-day and 6-month death rates were, respectively, 8.4 (3.4 in left and 13.5 in right cases; P = 0.015), 11.8 (7.8 in left and 15.7 in right cases; P = 0.10) and 18.5% (12.4 in left and 24.7 in right cases; P = 0.033). On Cox regression, age, right pneumonectomy and the occurrence of postoperative cardiorespiratory complications (but not bronchial fistula) were related to the risk of death at 6 months. CONCLUSIONS The risk of death after pneumonectomy increases with time and strongly depends on the side of the operation (it is higher after right pneumonectomy) and on the occurrence of any postoperative cardiorespiratory complication. Neither hospital nor 30-day mortality should be reported as a valid outcome after pneumonectomy since they do not represent the real risk of the operation.

The values of intrapleural pressure before the removal of chest tube in non-complicated pulmonary lobectomies.

OBJECTIVES Digitalized chest drainage systems allow for quantification of air leak and measurement of intrapleural pressure. Little is known about the value of intrapleural pressure during the postoperative phase and its role in the recovering process after pulmonary resection. The objective of this investigation was to measure the values of pleural pressure immediately before the removal of chest tube after different types of pulmonary lobectomy. METHODS Prospective observational analysis on 203 consecutive patients submitted to pulmonary lobectomy during a 12-month period at two centres. Multiple measurements were recorded in the last hour before the removal of chest tube and averaged for the analysis. All patients were seated in bed in a 45° up-right position or in a chair, had a single chest tube and were not connected to suction during the evaluation period. Analysis of variance (ANOVA) was used to assess the differences in pleural pressure between different types of lobectomies. RESULTS The average maximum, minimum and differential pressures were -6.1, -19.5 and 13.3 cmH(2)O, respectively. The average pressures were similar in all types of lobectomies (ANOVA, P = 0.2) and ranged from -11 to -13 cmH(2)O, with the exception of right upper bilobectomy (-20 cmH(2)O, all P-values vs. other types of lobectomies <0.05). Similar values were also recorded for maximum pressures (range -4.4 to -8.4 cmH(2)O) and minimum pressures (-31.6 cmH(2)O vs. ranged from -15.4 to -20.5 cmH(2)O, all P-values <0.01). The average pleural pressure was not associated with FEV1 (P = 0.9), DLCO (P = 0.2) or FEV1/FVC ratio (P = 0.6), when tested with linear regression. Similarly, the average pleural pressure was similar in patients with and without COPD (-12.1 vs. -13.0 cmH(2)O, P = 0.4). The ANOVA test was used to assess differences in pressures between different lobectomies. CONCLUSIONS The so-called water seal status may actually correspond to intrapleural pressures ranging from -13 to -20 cmH(2)O. Modern electronic chest drainage devices allow a stable control of the intrapleural pressure. Thus, the values found in this study may be used as target pressures for different types of lobectomies, in order to favour lung recovery after surgery.

Chest drainage suction decreases differential pleural pressure after upper lobectomy and has no effect after lower lobectomy

BACKGROUND AND OBJECTIVE To our knowledge, no reports have been published describing the effect of suction on pleural pressures after different types of lobectomy. Improving knowledge of pleural physiology in the postoperative period could lead to better postoperative care. The aim of this investigation is to evaluate the effect of postoperative suction on inspiratory, expiratory and differential pleural pressures after upper or lower lobectomy. METHODS Records of intrapleural pressures from 24 lobectomy patients (operated on in two different institutions) were selected for study. All patients had normal preoperative pulmonary function tests (forced expiratory volume in 1s (FEV1) >80% and forced vital capacity (FVC)/FEV1 >70%), and neither postoperative air leak nor any other postoperative complication. We selected six cases of each type of lobectomy (right upper lobectomy (RUL), right lower lobectomy (RLL), left upper lobectomy (LUL) and left lower lobectomy (LLL)). In three cases of each group, no suction was indicated, while in the other three cases, chest tubes were placed under 15 cm H(2)O suction, according to the standard local perioperative care protocol in each participating centre. Inspiratory and expiratory pleural pressures were measured at 2-min intervals by an electronic device using a DigiVent (Millicore A.B., Sweden) suction chamber. Recording started 5-10h after closing the chest, and included 5 consecutive hours during the first postoperative night, with the patients at rest in 30-45 degrees sitting position. There was no evidence of pneumothorax during the recording time. The influence of lobectomy site (upper or lower) and suction on inspiratory, expiratory and differential pressures were evaluated by Students t-tests. RESULTS In the group of cases under no suction, upper lobectomy patients had larger differential pressures (22.6 in upper vs 11.5 cm H(2)O in lower lobectomy cases, p<0.001), differential pressure decreased in patients under suction (9.1 in upper vs 11.1 cm H(2)O in lower lobectomy cases, p<0.001) and the effect was mainly due to a less negative inspiratory pressure. CONCLUSION Pleural suction leads to a large decrease of differential pleural pressure after upper pulmonary lobectomy. The influence of this finding on postoperative work of breathing in the early postoperative period remains to be investigated.