Marcelo F. Jiménez

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to the decision of their counterpart, evaluated chest tube withdrawal criteria and noted whether the tube should be withdrawn or not.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.

Recalibration of the Revised Cardiac Risk Index in Lung Resection Candidates

BACKGROUND The revised cardiac risk index (RCRI) has been proposed as a tool for cardiac risk stratification before lung resection. However, the RCRI was originally developed from a generic surgical population including a small group of thoracic patients. The objective of this study was to recalibrate the RCRI in candidates for major lung resections to provide a more specific instrument for cardiac risk stratification. METHODS One thousand six hundred ninety-six patients who underwent lobectomy (1,426) or pneumonectomy (270) in two centers between the years of 2000 and 2008 were analyzed. Stepwise logistic regression and bootstrap analyses were used to recalibrate the six variables comprising the RCRI. The outcome variable was occurrence of major cardiac complications (cardiac arrest, complete heart block, acute myocardial infarction, pulmonary edema, or cardiac death during admission). Only those variables with a probability of less than 0.1 in more than 50% of bootstrap samples were retained in the final model and proportionally weighted according to their regression estimates. RESULTS The incidence of major cardiac morbidity was 3.3% (57 patients). Four of the six variables present in the RCRI were reliably associated with major cardiac complications: cerebrovascular disease (1.5 points), cardiac ischemia (1.5 points), renal disease (1 point), and pneumonectomy (1.5 points). Patients were grouped into four classes according to their recalibrated RCRI, predicting an incremental risk of cardiac morbidity (p < 0.0001). Compared with the traditional RCRI, the recalibrated score had a higher discrimination (c indexes, 0.72 versus 0.62; p = 0.004). CONCLUSIONS The recalibrated RCRI can be reliably used as a first-line screening instrument during cardiologic risk stratification for selecting those patients needing further cardiologic testing from those who can proceed with pulmonary evaluation without any further cardiac tests.

Prospective study on video-assisted thoracoscopic surgery in the resection of pulmonary nodules: 209 cases from the Spanish Video-Assisted Thoracic Surgery Study Group

OBJECTIVE The diagnosis of pulmonary nodules has become one of the main indications of video-assisted thoracoscopic surgery (VATS), especially for small nodules not accessible by bronchoscopy or by percutaneous transthoracic needle aspiration. In this study we evaluate the indications, diagnostic safety, complications, and technical difficulty of VATS in the diagnosis of pulmonary nodules in Spain. MATERIALS AND METHODS We conducted a prospective study of 209 patients with one or more pulmonary nodules from a group of Spanish thoracic surgery divisions (The Spanish Video-assisted Thoracic Surgery Study Group). Data was collected and evaluated on variables contained on a questionnaire including demographic information, characteristics of the nodules, identification methods, surgical technique, morbidity and mortality rates, and diagnostic yield. RESULTS The mean size of the nodules was 1.9 cm (range 0.3-5 cm). A total of 93.3% were peripheral. A diagnosis was established in 100% of the cases. In this study, 51.1% of lesions were benign and 48.8% were malignant. In 16.3% of cases, a conversion to thoracotomy was needed. The morbidity was 9.6% and the mortality 0.5%. We found a relationship between the size of a nodule and a diagnosis of malignancy (P=0.019) and between a central location and a need to convert to thoracotomy (P=0.002). Patients with nodules >2 cm had a greater risk of complications (P=0.0001). CONCLUSIONS In the diagnosis of pulmonary nodules, VATS has a specificity of 100% and a low mortality rate. The probability of developing complications is higher when the nodule is >2 cm.

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.

Prediction of postoperative morbidity after lung resection using an artificial neural network ensemble

OBJECTIVE To propose an ensemble model of artificial neural networks (ANNs) to predict cardio-respiratory morbidity after pulmonary resection for non-small cell lung cancer (NSCLC). METHODS Prospective clinical study was based on 489 NSCLC operated cases. An artificial neural network ensemble was developed using a training set of 348 patients undergoing lung resection between 1994 and 1999. Predictive variables used were: sex of the patient, age, body mass index, ischemic heart disease, cardiac arrhythmia, diabetes mellitus, induction chemotherapy, extent of resection, chest wall resection, perioperative blood transfusion, tumour staging, forced expiratory volume in 1s percent (FEV(1)%), and predicted postoperative FEV(1)% (ppoFEV(1)%). The analysed outcome was the occurrence of postoperative cardio-respiratory complications prospectively recorded and codified. The artificial neural network ensemble consists of 100 backpropagation networks combined via a simple averaging method. The probabilities of complication calculated by ensemble model were obtained to the actual occurrence of complications in 141 cases operated on between January 2000 and December 2001 and a receiver operating characteristic (ROC) curve for this method was constructed. RESULTS The prevalence of cardio-respiratory morbidity was 0.25 in the training and 0.30 in the validation series. The accuracy for morbidity prediction (area under the ROC curve) was 0.98 by the ensemble model. CONCLUSION In this series an artificial neural network ensemble offered a high performance to predict postoperative cardio-respiratory morbidity.

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.

Utility of standardized exercise oximetry to predict cardiopulmonary morbidity after lung resection

OBJECTIVES To evaluate if desaturation, measured by finger oximetry on standardized exercise, accurately predicts cardiopulmonary morbidity after pulmonary resection. METHODS A prospective observational clinical study was carried out on 81 consecutive lung carcinoma patients scheduled for pulmonary resection from February 1998 to March 1999. Finger oximetry was monitored during an incremental to exhaustion cycle exercise test. The presence or absence of desaturation (cut-off value 90%) during exercise was recorded. Other independent analyzed variables were: age of the patient (over 75th percentile), body-mass index (BMI) (over 75th percentile), presence of major cardiovascular co-morbidity, and calculated postoperative FEV1% (under 25th percentile) according to the number of resected segments (ppoFEV1%). Postoperative cardiopulmonary morbidity was the evaluated dependent outcome. Fishers exact test and risk calculation on contingency tables were used for statistical analysis. RESULTS A lobectomy was performed in 62 cases, a pneumonectomy was performed in 16 cases, and a segmentectomy was performed in three cases. The mean age of the patients was 63.6 years (SD 10.3, range 34-79 years, 75th percentile 72 years), the mean BMI was 25.9 (SD 4.9, range 16.9-38.1, 75th percentile 29.3), and the mean ppoFEV1% was 64.1 (SD 2016.1, range 29.5-98.6, 25th percentile 50.5). In 14 patients exercise desaturation was registered. Postoperative cardiopulmonary morbidity was presented in 32 cases (five deaths). No correlation was found between postoperative morbidity and any of the following variables: age of the patient, BMI, and co-morbidity. On univariate analysis only low ppoFEV1% (P<0.001) was associated with the outcome, so no multivariate analysis has been carried out. CONCLUSIONS We have shown that desaturation during standardized exercise in this series adds no relevant information to predict postoperative cardiorespiratory morbidity after lung resection.

Utilidad de la punción transbronquial y la mediastinoscopia en la estadificación ganglionar mediastínica del carcinoma broncogénico no microcítico. Estudio preliminar

Estudio preliminar que tiene por objetivo conocer la sensibilidad (S) y especificidad (E) de la puncion transbronquial (PTB) en comparacion con la mediastinoscopia/me- diastinotomia anterior (MED/MEDA), y/o toracotomia en la estadificacion ganglionar mediastinica del carcinoma no microcitico (CNM). Se analizo la S y E de la TAC como tecnica utilizada para la seleccion de pacientes. Fueron evaluados 33 pacientes con CNM sin metastasis a distancia y con buena funcion pulmonar. Se realizo una TAC toracica previa a la broncoscopia en 27 enfermos y antes de la cirugia en el resto. La estadificacion por PTB se realizo en las regiones ganglionares consideradas patologicas en la TAC y en la region subcarinal cuando no se pudo disponer de la informacion de la TAC antes de realizar la broncoscopia. Los resultados de la PTB se compararon con la MED/MEDA y/o toracotomia. La prevalencia de enfermedad ganglionar metastasica fue del 47%. En 24 pacientes la TAC detecto ganglios mediastinicos agrandados y en 9 casos el estudio ganglionar mediastinico por imagen fue considerado normal. La S y E de la TAC fue del 93 y 54%, con un valor predictivo positivo (VPP) del 68% y un valor predictivo negativo (VPN) del 87,5%. Para la MED/MEDA la S fue del 73% y la E del 100%, siendo los VPP y VPN del 100 y 75%, respectivamente. La S y E de la PTB fueron, respectivamente, del 36 y del 92%, con un VPP del 83% y un VPN del 57%. Un paciente sufrio un neumotorax con empiema pleural tras la MED que pudo ser evitado al ser previamente positiva la PTB. La PTB es una tecnica util y segura en la estadificacion ganglionar del CNM. Aunque la sensibilidad de la PTB es menor que la de la MED, la PTB permite analizar regiones de dificil acceso para la MED y puede hacer innecesaria la realizacion de esta ultima si se ha obtenido una puncion positiva para malignidad. La TAC toracica es una tecnica sensible pero poco especifica para determinar la presencia de afectacion ganglionar metastasica.

Morbidity after surgery for non-small cell lung carcinoma is not related to neoadjuvant chemotherapy

OBJECTIVES To compare postoperative morbidity and mortality rates in two groups of operated non-small cell lung carcinoma patients (NSCLC) with or without induction chemotherapy. METHODS This is a case-control study on 42 cases and 42 controls. Cases (Group A) underwent induction chemotherapy. Chemotherapy indications and regimens were variable. Control cases (Group B) were randomly selected among 494 NSCLC comparable patients operated on in the same period of time. The selection criteria for operation were the same in both groups. Dependent outcomes were operative death and complications. Independent selected variables were: age, co-morbidity, predicted postoperative FEV1% (1 s forced expiratory volume in percentage), type of surgery and clinical and pathological staging. All postoperative events and independent variables were prospectively registered. Chi-square and risk calculations on contingence tables and one-way ANOVA have been tested. RESULTS Both series are comparable in demographics, preoperative variables and type of surgery. No mortality has been registered. In Group A, the overall morbidity was 26.2% (11 out of 42 cases), and in Group B, this was 42.9% (18 out of 42 cases; P=0.084). Morbidity was not related to the type of surgery (pneumonectomy vs. other; P=0.205 in Group A and P=0.08 in Group B). Pathological staging did not influence the postoperative outcome, either in Group A (P=0.72; odds ratio, 1.515; 95% confidence interval (CI), 0.375-6.122) or Group B (P=0.299; odds ratio, 0.4; 95% CI, 0.089-1.797). CONCLUSIONS Induction chemotherapy in NSCLC has no influence on postoperative morbidity.

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.