M-quantile regression shrinkage and selection via the Lasso and Elastic Net to assess the effect of meteorology and traffic on air quality.

In this work, we intersect data on size-selected particulate matter (PM) with vehicular traffic counts and a comprehensive set of meteorological covariates to study the effect of traffic on air quality. To this end, we develop an M-quantile regression model with Lasso and Elastic Net penalizations. This allows (i) to identify the best proxy for vehicular traffic via model selection, (ii) to investigate the relationship between fine PM concentration and the covariates at different M-quantiles of the conditional response distribution, and (iii) to be robust to the presence of outliers. Heterogeneity in the data is accounted by fitting a B-spline on the effect of the day of the year. Analytic and bootstrap-based variance estimates of the regression coefficients are provided, together with a numerical evaluation of the proposed estimation procedure. Empirical results show that atmospheric stability is responsible for the most significant effect on fine PM concentration: this effect changes at different levels of the conditional response distribution and is relatively weaker on the tails. On the other hand, model selection allows to identify the best proxy for vehicular traffic whose effect remains essentially the same at different levels of the conditional response distribution.

Nonthyroidal illness syndrome (NTIS) in severe COVID-19 patients: role of T3 on the Na/K pump gene expression and on hydroelectrolytic equilibrium.

BACKGROUND: Nonthyroidal Illness Syndrome (NTIS) can be detected in many critical illnesses. Recently, we demonstrated that this condition is frequently observed in COVID-19 patients too and it is correlated with the severity the disease. However, the exact mechanism through which thyroid hormones influence the course of COVID-19, as well as that of many other critical illnesses, is not clear yet and treatment with T4, T3 or a combination of both is still controversial. Aim of this study was to analyze body composition in COVID-19 patients in search of possible correlation with the thyroid function. METHODS AND FINDINGS: We report here our experience performed in 74 critically ill COVID-19 patients hospitalized in the intensive care unit (ICU) of our University Hospital in Rome. In these patients, we evaluated the thyroid hormone function and body composition by Bioelectrical Impedance Analysis (BIA) during the acute phase of the disease at admission in the ICU. To examine the effects of thyroid function on BIA parameters we analyzed also 96 outpatients, affected by thyroid diseases in different functional conditions. We demonstrated that COVID-19 patients with low FT3 serum values exhibited increased values of the Total Body Water/Free Fat Mass (TBW/FFM) ratio. Patients with the lowest FT3 serum values had also the highest level of TBW/FFM ratio. This ratio is an indicator of the fraction of FFM as water and represents one of the best-known body-composition constants in mammals. We found an inverse correlation between FT3 serum values and this constant. Reduced FT3 serum values in COVID-19 patients were correlated with the increase in the total body water (TBW), the extracellular water (ECW) and the sodium/potassium exchangeable ratio (Nae:Ke), and with the reduction of the intracellular water (ICW). No specific correlation was observed in thyroid patients at different functional conditions between any BIA parameters and FT3 serum values, except for the patient with myxedema, that showed a picture similar to that seen in COVID-19 patients with NTIS. Since the Na+/K+ pump is a well-known T3 target, we measured the mRNA expression levels of the two genes coding for the two major isoforms of this pump. We demonstrated that COVID-19 patients with NTIS had lower levels of mRNA of both genes in the peripheral blood mononuclear cells (PBMC)s obtained from our patients during the acute phase of the disease. In addition, we retrieved data from transcriptome analysis, performed on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM)s treated with T3 and we demonstrated that in these cells T3 is able to stimulate the expression of these two genes in a dose-dependent manner. CONCLUSIONS: In conclusion, we demonstrated that measurement of BIA parameters is a useful method to analyze water and salt retention in COVID-19 patients hospitalized in ICU and, in particular, in those that develop NTIS. Our results indicate that NTIS has peculiar similarities with myxedema seen in severe hypothyroid patients, albeit it occurs more rapidly. The Na+/K+ pump is a possible target of T3 action, involved in the pathogenesis of the anasarcatic condition observed in our COVID-19 patients with NTIS. Finally, measurement of BIA parameters may represent good endpoints to evaluate the benefit of future clinical interventional trials, based on the administration of T3 in patients with NTIS.

Mixed-frequency quantile regressions to forecast value-at-risk and expected shortfall.

Although quantile regression to calculate risk measures is widely established in the financial literature, when considering data observed at mixed-frequency, an extension is needed. In this paper, a model is built on a mixed-frequency quantile regressions to directly estimate the Value-at-Risk (VaR) and the Expected Shortfall (ES) measures. In particular, the low-frequency component incorporates information coming from variables observed at, typically, monthly or lower frequencies, while the high-frequency component can include a variety of daily variables, like market indices or realized volatility measures. The conditions for the weak stationarity of the daily return process are derived and the finite sample properties are investigated in an extensive Monte Carlo exercise. The validity of the proposed model is then explored through a real data application using two energy commodities, namely, Crude Oil and Gasoline futures. Results show that our model outperforms other competing specifications, on the basis of some popular VaR and ES backtesting test procedures.

Quantile hidden semi-Markov models for multivariate time series.

This paper develops a quantile hidden semi-Markov regression to jointly estimate multiple quantiles for the analysis of multivariate time series. The approach is based upon the Multivariate Asymmetric Laplace (MAL) distribution, which allows to model the quantiles of all univariate conditional distributions of a multivariate response simultaneously, incorporating the correlation structure among the outcomes. Unobserved serial heterogeneity across observations is modeled by introducing regime-dependent parameters that evolve according to a latent finite-state semi-Markov chain. Exploiting the hierarchical representation of the MAL, inference is carried out using an efficient Expectation-Maximization algorithm based on closed form updates for all model parameters, without parametric assumptions about the states' sojourn distributions. The validity of the proposed methodology is analyzed both by a simulation study and through the empirical analysis of air pollutant concentrations in a small Italian city. Supplementary Information: The online version contains supplementary material available at 10.1007/s11222-022-10130-1.

COVID-19 After Lung Resection in Northern Italy.

We reviewed surgical cases from 4 Thoracic Surgery departments in the Lombardia region of Italy, the area mostly affected by Coronavirus pandemic in Europe, with the aim to describe the impact of COVID-19 on the treatment of thoracic surgical patients. Clinical, radiological and laboratory data from patients who underwent lung resection from December 2019 to March 2020 were retrospectively collected until June 2020. Univariable Cox regression models were estimated to evaluate potential prognostic factors for developing COVID-19 and to investigate postoperative mortality among patients who developed symptomatic COVID-19 infection. We examined data from 107 patients. (74 lobectomies, 32 wedge/segmentectomies and 1 pneumonectomy). Twelve patients developed COVID-19 (Group 1), whereas 95 patients were not infected (Group 2). In Group 1, 6 patients (50%) died from complications related to infection; in Group 2, one patient (1%) died because of non-COVID-19-related causes. Median days from surgery to first symptoms, CT confirmation, clinical confirmation and PCR positivity was 48.1, 54.3, 55.1, and 55.2 respectively. At univariable analysis, DLCO/VA% (P = 0.008), duration of the surgery (P = 0.009), smoking history (pack/year) (P < 0.001), BMI (P< 0.001) and number of segments resected (P = 0.010) were associated with COVID-19 onset. Moreover, CCI (P < 0.001), DLCO/VA% (P = 0.002), cigarette pack/year (P < 0.001), BMI (P < 0.001) and COVID-19 (P < 0.001) were associated with death. Patients who undergo lung resection and then develop symptomatic COVID-19 infection are at higher risk of developing severe respiratory complications and postoperative death. Insidious symptoms' onset may lead to a delay in diagnosis. We suggest two mitigating strategies: (1) Improve symptoms surveillance and isolation during recovery period, (2) Be aware of a potential greater risk of developing symptomatic COVID-19 and death correlated with elevated CCI, BMI, smoking history, DLCO/VA%, number of resected segments and duration of surgery.

3D Reconstruction Model of an Extra-Abdominal Desmoid Tumor: A Case Study.

In recent years, three-dimensional reconstruction (3DR) models have become a standard tool in several medical fields such as education, surgical training simulation, patient-doctor communication, and surgical planning. Postoncologic reconstructive surgery in thoracic diseases might benefit from 3DR models; however, limited data on this application have been published worldwide. In this paper, the aim was to report our experience with 3DR modeling to determine resection and plan the surgical reconstruction in a patient with a desmoid tumor of the chest wall. For a better understanding of the case study, we describe all the steps from acquiring computed tomography (CT) scans to the final 3D rendering. A 68-year-old, non-smoking man presented at our outpatient department with painless swelling of the right anterobasal chest wall. A thorax-abdomen-brain CT scan revealed homogenous solid tissue with a dense mass measuring 80 mm × 62 mm. The final 3D model was evaluated by the surgical team (three medical doctors), who found the model to be powerful. Based on the results and the accuracy of the model, the multidisciplinary team decided that the tumor was resectable. Consequently, a surgical plan based on the 3D model was developed to perform chest wall reconstruction after radical resection. The patient underwent right anterolateral thoracotomy at the seventh intercostal space, which confirmed the CT scan findings and revealed infiltration of the serratus muscle and medial portion of the diaphragm. A radical tumor en bloc resection with chest wall and diaphragm resection was performed. The full-thickness chest wall and diaphragm defects were reconstructed using two separate biological patches of a porcine dermal collagen implant (Permacol™ Surgical Implant). Postoperative X-ray revealed unremarkable findings; the patient had an uneventful recovery and was discharged 6 days after surgery. This case study illustrates that 3DR models enable a personalized approach to the treatment of desmoid tumors. Therefore, this approach should be developed further and studied systematically.

Long-term lung function following videothoracoscopic talc poudrage for primary spontaneous recurrent pneumothorax.

OBJECTIVE: Some concern still exists regarding long-term lung function following videothoracoscopic talc poudrage for primary spontaneous pneumothorax (PSP). We evaluated lung function at 5 years in a series of 100 patients surgically treated for PSP. METHODS: Out of 1065 patients treated for PSP by means of videothoracoscopic talc poudrage from September 1995 to January 2006, we consecutively enrolled 50 patients (33 males, 17 females, mean age: 24.22 years, median age: 24 years; range: 13-40 years) (group A) with no recurrence for functional evaluation with measurement of static and dynamic volumes (FEV1-FVC-TLC-RV), and DLCO at 60 months after surgery. Fifty patients (35 males, 15 females, mean age: 23.56 years; median age: 22.5 years; range: 16-37 years) underwent same pulmonary function tests 5 years after simple drainage for recurrent PSP because of refusal of surgery (group B). RESULTS: Pulmonary function tests showed (mean % value+/-SD for group A vs group B): FEV1 93+/-6.6 versus 95.4+/-6.4; FVC 98+/-6.5 versus 100.1+/-6.9; TLC 91.7+/-7.7 versus 94.36+/-5.8; RV 97+/-7 versus 99.2+/-4.9; DLCO 91.4+/-2.8 versus 91.98+/-4.2. No patient in both groups showed FEV1<80%. Analysis of mean difference of pulmonary function values was computed between group A and group B patients. CONCLUSIONS: No statistically significant differences in long-term lung function have been found between patients treated with pleural drainage only versus patients treated with videothoracoscopic talc poudrage for PSP. Lung function is not impaired by videothoracoscopic talc poudrage.

The Challenge of Treating Early-Stage Rheumatoid Arthritis: The Contribution of Mixed Treatment Comparison to Choosing Appropriate Biologic Agents.

BACKGROUND: Use of biologic drugs is approved for treatment in rheumatoid arthritis (RA), both in established disease and at the early stage of RA (ERA). Identification of ERA and an early therapeutic strategy would lead to greater clinical improvement. Only a few indirect comparisons of the efficacy of different biologic agents in established RA have been performed and, to date, no studies reporting direct comparisons have been performed in ERA. OBJECTIVE: The aim of this study was to compare, by use of a mixed treatment comparison (MTC), the efficacy profiles of biologic agents in ERA. METHODS: An extensive literature search was performed to identify results of randomized, controlled trials (RCTs) evaluating biologic agents at licensed doses to treat patients affected by ERA. The primary end points for the analysis were the American College of Rheumatology 20% improvement (ACR20), ACR50, and ACR70 responses from baseline to various times of follow-up. WinBUGS 1.4 software (MRC Biostatistics Unit, Cambridge, UK) was used to perform the analyses. The MTC results are reported as the relative risk of a response for every single treatment coadministered with methotrexate, versus methotrexate plus placebo, which was used as a comparator in all RCTs. RESULTS: Ten scientific papers met the study inclusion criteria and were included in the analysis. Data on the use of infliximab, adalimumab, etanercept, abatacept, golimumab, and rituximab were included. No studies reported on the use of certolizumab pegol or tocilizumab in ERA. All biologic agents coadministered with methotrexate proved to be more efficacious than methotrexate plus placebo in inducing ACR20, ACR50, and ACR70 responses. The biologic agent characterized by the highest probability of inducing an ACR70 response was adalimumab (33.28%). Etanercept was the biologic agent with the highest probability of inducing ACR20 and ACR50 responses, in comparison with all other biologic agents, with probability rates of 62.95 and 37.1%, respectively. CONCLUSION: In our analysis, adalimumab proved to be the biologic agent with the highest probability of inducing an ACR70 response in patients affected by ERA, while etanercept was the biologic agent with the highest probability of inducing ACR50 and ACR20 responses.

Efficacy of biological agents administered as monotherapy in rheumatoid arthritis: a Bayesian mixed-treatment comparison analysis.

BACKGROUND: Biological agents provide an important therapeutic alternative for rheumatoid arthritis patients refractory to conventional disease-modifying antirheumatic drugs. Few head-to-head comparative trials are available. PURPOSE: The aim of this meta-analysis was to compare the relative efficacy of different biologic agents indicated for use as monotherapy in rheumatoid arthritis. METHODS: A systemic literature search was performed on electronic databases to identify articles reporting double-blind randomized controlled trials investigating the efficacy of biologic agents indicated for monotherapy. Efficacy was assessed using American College of Rheumatology (ACR) 20, 50, and 70 criteria at 16-24 weeks. Relative efficacy was estimated using Bayesian mixed-treatment comparison models. Outcome measures were expressed as odds ratio and 95% credible intervals. RESULTS: Ten randomized controlled trials were selected for data extraction and analysis. Mixed-treatment comparison analysis revealed that tocilizumab offered 100% probability of being the best treatment for inducing an ACR20 response versus placebo, methotrexate, adalimumab, or etanercept. Likewise, for ACR50 and ACR70 outcome responses, tocilizumab had a 99.8% or 98.7% probability of being the best treatment, respectively, compared to other treatments or placebo. Tocilizumab increased the relative probability of being the best treatment (vs methotrexate) by 3.2-fold (odds ratio: 2.1-3.89) for all ACR outcomes. CONCLUSION: Tocilizumab offered the greatest possibility of obtaining an ACR20, ACR50, and ACR70 outcome vs other monotherapies or placebo.

Indirect comparison between subcutaneous biologic agents in ankylosing spondylitis.

BACKGROUND AND OBJECTIVE: There are four efficacious subcutaneous anti-tumor necrosis factor alpha (TNF-alpha) agents used for the therapy of ankylosing spondilitis (AS), but apparently little or no differences in their effectiveness was proven. By this study, we aimed to compare Assessment in Ankylosing Spondylitis Response Criteria 20 response patterns (ASAS20) between subcutaneous approved biological agents in patients affected by ankylosing spondylitis by means of a mixed treatment comparison of different randomized controlled trials (RCTs) on the efficacy of biological therapies. METHODS: A search in scientific literature was performed to identify the most complete collection of RCTs available on the selected topic. Similarly designed double-blind, randomized, placebo-controlled trials investigating the efficacy of the subcutaneous and approved TNF-alpha inhibitors such as etanercept, certolizumab pegol, golimumab and adalimumab in the treatment of ankylosing spondylitis patients were identified. The endpoint of interest was ASAS20 response criterium at 12 weeks. Results were analysed simultaneously using Bayesian mixed treatment comparison techniques. Results were expressed as odds ratio (OR) of positive ASAS20 response and associated 95 % credible intervals (CrIs). The probability of being the best treatment was also reported. RESULTS: Only five RCTs matched the inclusion criteria for consequent data extraction and analysis. Mixed treatment comparison of data from such RCTs demonstrated that all subcutaneous anti-TNF-alpha agents are more effective in inducing an ASAS20 response than placebo. Data from 24 weeks' follow-up were not taken into account as early escape granted in some of the studies made results at 24 weeks unmatchable. In our analysis, golimumab proved to be the drug that more probably represents the best choice for achieving ASAS20 response at 12 weeks, although no differences were observed when comparing directly every single subcutaneous anti-TNF-alpha agent against another. CONCLUSIONS: Even if the mixed treatment comparisons between adalimumab, golimumab, certolizumab pegol and etanercept did not show a statistically significant difference, this analysis, based on data from only five RCTs, suggests that golimumab, compared to placebo, may be the drug that provides the highest probability of achieving ASAS20 response in AS patients naive to biologic treatments at 12 weeks.

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.

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.

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.

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.

Videothoracoscopic talc poudrage in primary spontaneous pneumothorax: a single-institution experience in 861 cases.

OBJECTIVE: We sought to evaluate the outcome of 861 patients treated with videothoracoscopic talc poudrage for primary spontaneous pneumothorax. METHODS: From September 1995 through January 2004, a total of 861 patients (578 male, 283 female, mean age 28.6 years) underwent videothoracoscopy for recurrent and complicated primary spontaneous pneumothorax. Patients were treated with videothoracoscopic talc poudrage only (group A: Vanderschueren's stage I, 196 patients; stage II, 112 patients) or videothoracoscopic talc poudrage plus stapling of the blebs/bullae (group B: stage III, 391 patients; stage IV 162 patients). Follow-up included clinical interview and chest radiography (805 patients). In 26 patients (follow-up longer than 5 years), respiratory function was investigated to determine residual volume and diffusing lung capacity. RESULTS: No operative deaths occurred. No patient had adult respiratory distress syndrome. Postoperative complications occurred in 29 patients (3.36%). The conversion rate to an open procedure was 0.46% (4/861). After a mean follow-up of 52.5 months, 14 patients had recurrences (1.73%). The recurrence rate was 2.41% (7/290) in group A and 1.359% (7/515) in group B (chi2 value: 1.207389; P:.27; odds ratio: 0.56; 95% confidence interval: 0.20-1.62). Results of respiratory function tests were within normal ranges (80% or more of predictive value) in all 26 patients. CONCLUSIONS: Videothoracoscopic talc poudrage achieves a high success rate in the treatment of primary spontaneous pneumothorax with a very low morbidity rate. Recurrences show a statistically significant relationship (P:.037) with smoking habits.

Abdominal rectopexy for complete rectal prolapse: preliminary results of a new technique.

PURPOSE: Although the technique for the surgical repair of rectal prolapse has advanced over the years, no ideal procedure has been found. We aim to test a new surgical procedure for abdominal rectopexy that uses the greater omentum to support the rectum below the rectopexy, to reconstruct the anorectal angle and dispense with the need for synthetic mesh, thus reducing the risk of infection. METHODS: A series of ten patients, all young and medically fit, underwent repair surgery for rectal prolapse with the new rectopexy technique. Some patients had concomitant sigmoidectomy. Preoperative and postoperative assessment included a clinical examination, anal manometry and defecography. RESULTS: Follow-up lasted a mean of 56.4 months. None of the patients had recurrent rectal prolapse or infection. Postoperative assessment at 24 months disclosed significant improvements in all the bowel and sphincter variables assessed. The 8 patients who had severe incontinence preoperatively had notably improved and 4 were fully continent, 3 moderately incontinent, and only 1 patient had persistently high levels of incontinence. In only 1 patient who initially had severe incontinence, continence completely regressed and severe constipation developed. Maximal basal pressure values increased significantly after surgery (p=0.0025), although they increased slightly less evidently in patients in whom marked incontinence persisted at postoperative follow-up. Maximal voluntary contraction pressure also increased significantly after surgery (p=0.0054), although the values changed less than those for basal pressure. During rest, squeeze and straining, and in all the patients who regained continence, even those who recovered it only partly, surgery substantially reduced the anorectal angle. The reduction during rest was statistically significant (p=0.0062). CONCLUSIONS: The rectopexy technique we tested in patients with rectal prolapse avoids the need for synthetic mesh, and provides good results in terms of bowel and sphincter function, without infection or recurrence.