Lea Petrella

Chronic postpneumonic pleural empyema: comparative merits of thoracoscopic versus open decortication.

OBJECTIVE We seek to evaluate the comparative merits of thoracoscopic versus open decortication in the surgical management of patients with chronic postpneumonic pleural empyema. METHODS From January 1996 to December 2006, 308 patients (180 males, 128 females, mean age: 56.3 years, range: 17-82 years) with chronic postpneumonic pleural empyema underwent decortication after failure of conservative treatment. RESULTS Decortication was performed by open thoracotomy in 123 (39.9%) patients (OT) and by videothoracoscopy (VT) in 185 (60.1%). Mortality was 1.29% (4/308). Morbidity was 21.1% (65/308). At 6 months follow-up, three VT patients showed recurrent empyema and underwent re-do surgery by video-assisted-thoracoscopy (VATS) (one patient) or by thoracotomy (two patients). The videothoracoscopic approach showed statistically significant better results in terms of in-hospital postoperative (day 1 and day 7), pain (p<0.0001), postoperative air leak (p=0.004), operative time (p<0.0001), hospital stay (p=0.020) and time to return to work (p<0.0001). The analysis of postoperative pain at 6 months follow-up showed no significant differences among the different groups. CONCLUSIONS In the light of our experience, videothoracoscopic decortication appears to be the surgical treatment of choice for chronic postpneumonic pleural empyema even if a multicentric-randomised trial should be performed before videothoracoscopic decortication becomes the gold standard for the treatment of pleural empyema.

Predictors of survival in patients with locally advanced thymoma and thymic carcinoma (Masaoka stages III and IVa)

OBJECTIVE We sought to evaluate factors influencing long-term survival of patients with locally advanced thymoma/thymic carcinoma (Masaoka stages III and IVa) treated by immediate surgery or induction therapy plus surgery. METHODS From January 1991 to April 2007, we surgically treated 61 patients with locally advanced thymoma/thymic carcinoma (Masaoka stages III and IVa). Staging included total body computed tomography (CT) scan in all patients, and chest magnetic resonance imaging (MRI) in 27 selected patients. All patients had histological confirmation before surgery. Thirty-one patients (group A) underwent induction chemotherapy followed by surgery. Thirty patients (group B) underwent immediate surgery. Thirty-four patients (group A: 13; group B: 17) received postoperative radiation therapy. RESULTS No intra-operative mortality was reported. World Health Organization (WHO) histological classification included 19 AB, four B1, seven B2 and 13 B3 thymomas and 18 thymic carcinomas. Thirty-four patients were Masaoka stage III (group A: 18; group B: 16) and 27 patients were stage IVa (group A: 13; group B: 14). After a median follow-up of 77 months, six patients of group A and seven patients of group B died of disease. The overall 10-year survival rate was 50.6%. The 10-year survival rate was 57.9% in group A and 38.1% in group B (p=0.03). Multivariate analysis showed complete resection (p=0.02), Masaoka stage (III vs IVa) (p=0.02), induction chemotherapy (group A vs group B) (p=0.003) and histological WHO subtype (AB vs B1, B2 and B3) (p=0.01) to be statistically significant independent predictors of survival. Sex, age and adjuvant radiation therapy showed no statistically significant difference. CONCLUSIONS Complete resection, Masaoka stage, induction chemotherapy and histological WHO classification showed to be independent predictors of survival in locally advanced thymoma/thymic carcinoma.

A multivariate copula‐based framework for dealing with hazard scenarios and failure probabilities

This paper is of methodological nature, and deals with the foundations of Risk Assessment. Several international guidelines have recently recommended to select appropriate/relevant Hazard Scenarios in order to tame the consequences of (extreme) natural phenomena. In particular, the scenarios should be multivariate, i.e., they should take into account the fact that several variables, generally not independent, may be of interest. In this work, it is shown how a Hazard Scenario can be identified in terms of (i) a specific geometry and (ii) a suitable probability level. Several scenarios, as well as a Structural approach, are presented, and due comparisons are carried out. In addition, it is shown how the Hazard Scenario approach illustrated here is well suited to cope with the notion of Failure Probability, a tool traditionally used for design and risk assessment in engineering practice. All the results outlined throughout the work are based on the Copula Theory, which turns out to be a fundamental theoretical apparatus for doing multivariate risk assessment: formulas for the calculation of the probability of Hazard Scenarios in the general multidimensional case ( d≥2) are derived, and worthy analytical relationships among the probabilities of occurrence of Hazard Scenarios are presented. In addition, the Extreme Value and Archimedean special cases are dealt with, relationships between dependence ordering and scenario levels are studied, and a counter-example concerning Tail Dependence is shown. Suitable indications for the practical application of the techniques outlined in the work are given, and two case studies illustrate the procedures discussed in the paper.

Surgical treatment of benign neurogenic tumours of the mediastinum: a single institution report §

OBJECTIVE Neurogenic tumours of the mediastinum are uncommon neoplasms arising from nerve tissues within the thorax. We sought to evaluate and compare the outcome following surgical resection of such tumours by VATS, open thoracotomy, and by either combined with hemilaminectomy. METHODS From February 1992 to March 2007, 93 patients underwent surgical resection of neurogenic tumours of the mediastinum in our institution. A videothoracoscopic approach was used in 57 cases (61.3%) (group V), of which 44 underwent VATS only and 13 required conversion to open approach. In the remaining 36 cases, 32 patients underwent thoracotomy (group T) and 4 had combined procedure with the neurosurgeons (group N). RESULTS No postoperative mortality was reported. Postoperative morbidity rate was 23.6% (22/93; 14 of group T, 4 of group N, and 4 of group V; p<0.0001). Histology showed benign neurogenic tumours in all patients. Statistical analysis showed differences between the two groups (group V and T respectively) in mean operative time (111.3+/-58.2 min vs 149.06+/-77.05 min; p: 0.01), median postoperative stay (4 days vs 6 days p: 0.0009) and median postoperative pain on day 1, day 7 and 1 month after surgery (respectively p<0.0001, p<0.0001 and p: 0.001). At a mean follow-up of 73 months no patients showed recurrence of the tumour. CONCLUSIONS VATS represents the gold standard for the treatment of benign neurogenic tumours of the mediastinum with better results in terms of morbidity, operative time, postoperative stay and postoperative pain compared to open approach. Dumbbell tumours require a combined thoracic and neurosurgical approach.

How individual characteristics affect university students drop-out: a semiparametric mixed-effects model for an Italian case study

University drop-out is a topic of increasing concern in Italy as well as in other countries. In empirical analysis, university drop-out is generally measured by means of a binary variable indicating the drop-out versus retention. In this paper, we argue that the withdrawal decision is one of the possible outcomes of a set of four alternatives: retention in the same faculty, drop out, change of faculty within the same university, and change of institution. We examine individual-level data collected by the administrative offices of “Sapienza” University of Rome, which cover 117 072 students enrolling full-time for a 3-year degree in the academic years from 2001/2002 to 2006/2007. Relying on a non-parametric maximum likelihood approach in a finite mixture context, we introduce a multinomial latent effects model with endogeneity that accounts for both heterogeneity and omitted covariates. Our estimation results show that the decisions to change faculty or university have their own peculiarities, thus we suggest that caution should be used in interpreting results obtained without modeling all the relevant alternatives that students face.

The Rationale for Treatment of Postresectional Bronchopleural Fistula: Analysis of 52 Patients

BACKGROUND Bronchopleural fistulas are a major therapeutic challenge. We have reviewed our experience to establish the best choice of treatment. METHODS From January 2001 to December 2013, the records of 3,832 patients who underwent pulmonary anatomic resections were retrospectively reviewed. RESULTS The overall incidence of bronchopleural fistulas was 1.4% (52 of 3,832): 1.2% after lobectomy and 4.4% after pneumonectomy. Pneumonectomy vs lobectomy, right-sided vs left-sided resection, and hand-sewn closure of the stump vs stapling showed a statistically significant correlation with fistula formation. Primary bronchoscopic treatment was performed in 35 of 52 patients (67.3%) with a fistula of less than 1 cm and with a viable stump. The remaining 17 patients (32.7%) underwent primary operation. The fistula was cured with endoscopic treatment in 80% and with operative repair in 88.2%. Cure rates were 62.5% after pneumonectomy and 86.4% after lobectomy. The cure rate with endoscopic treatment was 92.3% in very small fistulas, 71.4% in small fistulas, and 80% in intermediate fistulas. The cure rate after surgical treatment was 100% in small fistulas, 75% in intermediate fistulas, and 100% in very large fistulas. Morbidity and mortality rates were 5.8% and 3.8%, respectively. CONCLUSIONS The bronchoscopic approach shows very promising results in all but the largest bronchopleural fistulas. Very small, small, and intermediate fistulas with a viable bronchial stump can be managed endoscopically, using mechanical abrasion, polidocanol sclerosing agent, and cyanoacrylate glue. Bronchoscopic treatment can be repeated, and if it fails, does not preclude subsequent successful surgical treatment.

Prior Density-Ratio Class Robustness in Econometrics

This article provides a generic, very fast method for computing exact density-ratio class bounds on posterior expectations, given the output of a posterior simulator. It illustrates application of the method in an econometric model of typical complexity. In this model, the exact bounds for expectations of some functions of interest are well approximated by the established asymptotic approximation but others are not. Software for the computations is publicly available in a variety of programming languages.

Conditional risk based on multivariate hazard scenarios

We present a novel methodology to compute conditional risk measures when the conditioning event depends on a number of random variables. Specifically, given a random vector

Censored Exponential Data: Large Deviations for MLEs and Posterior Distributions

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