Extended pleurectomy decortication and chemotherapy versus chemotherapy alone for pleural mesothelioma (MARS 2): a phase 3 randomised controlled trial

BACKGROUND

Extended pleurectomy decortication for complete macroscopic resection for pleural mesothelioma has never been evaluated in a randomised trial. The aim of this study was to compare outcomes after extended pleurectomy decortication plus chemotherapy versus chemotherapy alone.

METHODS

MARS 2 was a phase 3, national, multicentre, open-label, parallel two-group, pragmatic, superiority randomised controlled trial conducted in the UK. The trial took place across 26 hospitals (21 recruiting only, one surgical only, and four recruiting and surgical). Following two cycles of chemotherapy, eligible participants with pleural mesothelioma were randomly assigned (1:1) to surgery and chemotherapy or chemotherapy alone using a secure web-based system. Individuals aged 16 years or older with resectable pleural mesothelioma and adequate organ and lung function were eligible for inclusion. Participants in the chemotherapy only group received two to four further cycles of chemotherapy, and participants in the surgery and chemotherapy group received pleurectomy decortication or extended pleurectomy decortication, followed by two to four further cycles of chemotherapy. It was not possible to mask allocation because the intervention was a major surgical procedure. The primary outcome was overall survival, defined as time from randomisation to death from any cause. Analyses were done on the intention-to-treat population for all outcomes, unless specified. This study is registered with ClinicalTrials.gov, NCT02040272, and is closed to new participants.

FINDINGS

Between June 19, 2015, and Jan 21, 2021, of 1030 assessed for eligibility, 335 participants were randomly assigned (169 to surgery and chemotherapy, and 166 to chemotherapy alone). 291 (87%) participants were men and 44 (13%) women, and 288 (86%) were diagnosed with epithelioid mesothelioma. At a median follow-up of 22·4 months (IQR 11·3-30·8), median survival was shorter in the surgery and chemotherapy group (19·3 months [IQR 10·0-33·7]) than in the chemotherapy alone group (24·8 months [IQR 12·6-37·4]), and the difference in restricted mean survival time at 2 years was -1·9 months (95% CI -3·4 to -0·3, p=0·019). There were 318 serious adverse events (grade ≥3) in the surgery group and 169 in the chemotherapy group (incidence rate ratio 3·6 [95% CI 2·3 to 5·5], p<0·0001), with increased incidence of cardiac (30 vs 12; 3·01 [1·13 to 8·02]) and respiratory (84 vs 34; 2·62 [1·58 to 4·33]) disorders, infection (124 vs 53; 2·13 [1·36 to 3·33]), and additional surgical or medical procedures (15 vs eight; 2·41 [1·04 to 5·57]) in the surgery group.

INTERPRETATION

Extended pleurectomy decortication was associated with worse survival to 2 years, and more serious adverse events for individuals with resectable pleural mesothelioma, compared with chemotherapy alone.

FUNDING

National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (15/188/31), Cancer Research UK Feasibility Studies Project Grant (A15895).

Costal margin injuries and trans-diaphragmatic intercostal hernia: Presentation, management and outcomes according to the Sheffield classification

BACKGROUND

Costal margin rupture (CMR) injuries are under-diagnosed and inconsistently managed, while carrying significant symptomatic burden. We hypothesized that the Sheffield Classification system of CMR injuries would relate to injury patterns and management options.

METHODS

Data were collected prospectively between 2006 and 2023 at a major trauma center in the United Kingdom. Computed tomography scans were interrogated and injuries were categorized according to the Sheffield Classification. Clinical, radiologic, management and outcome variables were assessed.

RESULTS

Fifty-four patients were included in the study. Intercostal hernia (IH) was present in 30 patients and associated with delayed presentation ( p = 0.004), expulsive mechanism of injury (i.e. such as occurs with coughing, sneezing, or retching), higher body mass index ( p < 0.001), and surgical management ( p = 0.02). There was a bimodal distribution of the level of the costal margin rupture, with IH Present and expulsive mechanism injuries occurring predominantly at the ninth costal cartilage, and IH Absent cases and other mechanisms at the seventh costal cartilage ( p < 0.001). There were correlations between the costal cartilage being thin at the site of the CMR and the presence of IH and expulsive etiology ( p < 0.001). Management was conservative in 23 and surgical in 31 cases. Extrathoracic mesh IH repairs were performed in 3, Double Layer Mesh Repairs in 8, Suture IH repairs in 5, CMR plating in 8, CMR sutures in 2, and associated Surgical Stabilization of Rib Fractures in 11 patients. There was one postoperative death. There were seven repeat surgical procedures in five patients.

CONCLUSION

The Sheffield Classification is associated statistically with presentation, related chest wall injury patterns, and type of definitive management. Further collaborative data collection is required to determine the optimal management strategies.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

The everlasting issue of prolonged air leaks after lobectomy for non-small cell lung cancer: A data-driven prevention planning model in the era of minimally invasive approaches

BACKGROUND AND OBJECTIVES

Prolonged air leaks (PAL) are the most frequent complication after lobectomy for non-small cell lung cancer, even in case of minimally invasive approaches. We developed a novel score to identify high-risk patients for PAL during minimally invasive lobectomy.

METHODS

A dedicated database was created. We investigated preoperative candidate features and specific intraoperative variables. Univariate and subsequent logistic regression analysis with bootstrap resampling have been used. Model performance has been assessed by reckoning the area under the receiver operating characteristics curve and the Hosmer-Lemeshow goodness of fit.

RESULTS

PAL (>5 days) occurred in 72 (15.69%) patients. Five variables emerged from the model. Each one was assigned a score to provide a cumulative scoring system: forced expiratory volume in 1 second below 86% (P = 0.004, 1.5 points), body mass index <24 ( P = 0.002, 1 point), active smoking ( P = 0.001, 1.5 points), incomplete fissures ( P = 0.004, 1.5 points), and adhesions ( P = 0.0001, 1 point). The new score provided a stratification into four risk classes.

CONCLUSIONS

The risk score incorporates either general or more specific variables, providing a risk stratification that could be readily applied intra- and postoperatively. Henceforth, specific technical and management measures could be properly allocated to curb PAL.

Evaluation of surgical approaches to anatomical segmentectomies: the transition to minimal invasive surgery improves hospital outcomes

Background

We aim to evaluate the transition process from open to video-assisted thoracoscopic surgery (VATS) anatomical segmentectomies in a regional thoracic surgical unit.

Methods

In a retrospective study from January 2013 to December 2015, we identified all anatomical segmentectomies performed in our unit. Pre, peri and postoperative data were compared between the three years (2013, 2014 and 2015) and according to operative approach. Thoracotomy after VATS intraoperative biopsy was considered a conversion for the purposes of the study.

Results

A total of 86 consecutive cases [56 females and 30 males, median age 70 years (range, 43 to 83 years); median FEV1 of 78% predicted (range, 41% to 126%)] were included. There was a significant change in the surgical approach with time. Fifty-two cases underwent VATS (73% via single-port) and 34 open surgeries, including nine conversions. There were no postoperative deaths in the VATS group and one in the open group. Operative outcomes were similar over time with no haemorrhagic events, equivalent R1 resection and nodal stations explored in all lymph node positive patients. In node negative cases however, open surgery was associated with more extensive mediastinal exploration. Patients in 2015 had a shorter hospital stay in comparison to those in previous years [median 4 days (range, 1-15 days) vs. median 6 days (range, 3-27 days), P=0.01]. There were no differences in the incidence of complications or readmissions to hospital over time.

Conclusions

The transition over a short period of time from open to single-port VATS segmentectomy has allowed us to significantly reduce postoperative hospital stay without compromising operative or postoperative outcomes.

Determining optimal fluid and air leak cut off values for chest drain management in general thoracic surgery

BACKGROUND

Chest drain duration is one of the most important influencing aspects of hospital stay but the management is perhaps one of the most variable aspects of thoracic surgical care. The aim of our study is to report outcomes associated with increasing fluid and air leak criteria of protocol based management.

METHODS

A 6-year retrospective analysis of protocolised chest drain management starting in 2007 with a fluid criteria of 3 mL/kg increasing to 7 mL/kg in 2011 to no fluid criteria in 2012, and an air leak criteria of 24 hours without leak till 2012 when digital air leak monitoring was introduced with a criteria of <20 mL/min of air leak for more than 6 hours. Patient data were obtained from electronic hospital records and digital chest films were reviewed to determine the duration of chest tube drainage and post-drain removal complications.

RESULTS

From 2009 to 2012, 626 consecutive patients underwent thoracic surgery procedures under a single consultant. A total of 160 did not require a chest drain and data was missing in 22, leaving 444 for analysis. The mean age [standard deviation (SD)] was 57±19 years and 272 (61%) were men. There were no differences in the incidence of pneumothoraces (P=0.191), effusion (P=0.344) or re-interventions (P=0.431) for drain re-insertions as progressively permissive criteria were applied. The median drain duration dropped from 1-3 days (P<0.001) and accordingly hospital stay reduced from 4-6 days (P<0.001).

CONCLUSIONS

Our results show that chest drains can be safely removed without fluid criteria and air leak of less than 20 mL/min with median drain duration of 1 day, associated with a reduced length of hospital stay.

Uniportal thoracoscopic management of middle lobe torsion after upper lobectomy

Lobar torsion is a rare but potentially life-threatening complication following pulmonary resection. Surgical management usually entails an exploratory thoracotomy and resection of the involved lobe if nonviable. We present the case of a 67-year-old woman diagnosed with right middle lobe torsion 5 days after thoracotomy and right upper lobectomy for squamous carcinoma of the lung. A thoracoscopic right middle lobectomy was successfully performed utilizing a single 4-cm port placed along the midaxillary line in the 5th intercostal space.

The left thoracotomy approach for excision of distal tracheal carcinoma in the presence of right-sided aorta

Tracheal primary carcinoma is a rare malignancy, and we believe that its presence in a patient with a right-sided aorta has not been described before. We report a case of a primary tracheal squamous carcinoma in a patient with a four-branched right-sided aortic arch. The patient underwent a tracheal resection approached by a left thoracotomy. The surgical exposure was excellent once the ligamentum arteriosum had been divided. All the aortic arch branches and the phrenic, vagus and recurrent laryngeal nerves were identified and preserved.

Accuracy of two scoring systems for risk stratification in thoracic surgery

We investigate the suitability of the two existing risk stratification systems available for predicting mortality in a cohort of patients undergoing lung resection under a single surgeon. Data from the 290 consecutive patients who underwent pulmonary resection between January 2008 and January 2011 were extracted from a prospective clinical data base. In-hospital mortality risk scores are calculated for every patient by using Thoracoscore and ESOS.01 and were compared with actual in-hospital mortality. The receiver operating characteristic (ROC) curve was used to establish how well the systems rank for predicting patient mortality. Actual in-hospital mortality was 3.1% (n = 9). Thoracoscore and ESOS values (mean ± SEM) were 4.93 ± 0.32 and 4.08 ± 0.41, respectively. The area under the ROC curve values for ESOS and Thoracoscore were 0.8 and 0.6, respectively. ESOS was reasonably accurate at predicting the overall mortality (sensitivity 88% and specificity 67%), whereas Thoracoscore was a weaker predictor of mortality (sensitivity 67% and specificity 53%). The ESOS score had better predictive values in our patient population and might be easier to calculate. Because of their low specificity, the use of these scores should be limited to the assessment of outcomes of surgical cohorts, but they are not designed to predict risks for individual patients.

Short-term perioperative treatment with ambroxol reduces pulmonary complications and hospital costs after pulmonary lobectomy: a randomized trial

OBJECTIVE

To assess in a randomized clinical trial the influence of perioperative short-term ambroxol administration on postoperative complications, hospital stay and costs after pulmonary lobectomy for lung cancer.

METHODS

One hundred and forty consecutive patients undergoing lobectomy for lung cancer (April 2006-November 2007) were randomized in two groups. Group A (70 patients): ambroxol was administered by intravenous infusion in the context of the usual therapy on the day of operation and on the first 3 postoperative days (1000 mg/day). Group B (70 patients): fluid therapy only without ambroxol. Groups were compared in terms of occurrence of postoperative complications, length of stay and costs.

RESULTS

There were no dropouts from either group and no complications related to treatment. The two groups were well matched for perioperative and operative variables. Compared to group B, group A (ambroxol) had a reduction of postoperative pulmonary complications (4 vs 13, 6% vs 19%, p=0.02), and unplanned ICU admission/readmission (1 vs 6, 1.4% vs 8.6%, p=0.1) rates. Moreover, the postoperative stay and costs were reduced by 2.5 days (5.6 vs 8.1, p=0.02) and 2765 Euro (2499 Euro vs 5264 Euro, p=0.04), respectively.

CONCLUSIONS

Short-term perioperative treatment with ambroxol improved early outcome after lobectomy and may be used to implement fast-tracking policies and cut postoperative costs. Nevertheless, other independent trials are needed to verify the effect of this treatment in different settings.

Computational patient-specific models based on 3-D ultrasound data to quantify uterine arterial flow during pregnancy

Information on uterine blood flow rate during pregnancy would widely improve our knowledge on feto-placental patho-physiology. Ultrasonographic flow rate evaluation requires the knowledge of the spatial velocity profiles throughout the investigated vessel; these data may be obtained from hemodynamic simulations with accurate computational models. Recently, computational models of superficial vessels have been created using 3-D ultrasound data; unfortunately, common reconstruction methods are unsuitable for the uterine arteries due to the low quality achievable of imaged deep vessels. In this paper a simplified spline-based technique was applied to create computational models for patient-specific simulations of uterine arterial heamodynamics. Moreover, a novel method to quantify the uterine flow rates was developed based on echo-Doppler measurements and computational data. Preliminary results obtained for four patients indicated a quite narrow range for the blood flow rate through the main uterine artery with large variability in the flow split between corporal and cervical branches. Furthermore, parabolic-like velocity profiles were obtained in the branching region of the different patients, suggesting a clinical use of averaged, not patient-specific, spatial velocity distribution coefficients for the blood flow rate calculation. The developed reconstruction method based on 3-D ultrasound imaging is efficient for creating realistic custom models of the uterine arteries. The results of the fluid dynamic simulations allowed us to quantify the uterine arterial flow and its repartition in normal pregnancies.

Peak oxygen consumption during cardiopulmonary exercise test improves risk stratification in candidates to major lung resection

BACKGROUND

The objective of this investigation was to assess the association of peak oxygen consumption (Vo(2)) with postoperative outcome in a prospective cohort of patients undergoing major lung resection for the treatment of lung cancer.

METHODS

Preoperative symptom-limited cardiopulmonary exercise testing (CPET) performed using cycle ergometry was conducted in 204 consecutive patients who had undergone pulmonary lobectomy or pneumonectomy. Peak Vo(2) was tested for possible association with postoperative cardiopulmonary complications and mortality. Logistic regression analysis, validated by a bootstrap analysis, was used to adjust for the effect of other perioperative factors. The role of peak Vo(2) in stratifying the surgical risk was further assessed in different groups of patients subdivided according to their cardiorespiratory status.

RESULTS

Logistic regression showed that peak Vo(2) was an independent and reliable predictor of pulmonary complications (p = 0.04). All six deaths occurred in patients with a peak Vo(2) of < 20 mL/kg/min (four deaths in patients with a peak Vo(2) of < 12 mL/kg/min). The mortality rate in this high-risk group was 10-fold higher (4 of 30 patients; 13%) compared to those with higher peak Vo(2) (p = 0.006). Compared to patients with a peak Vo(2) of > 20 mL/kg/min, those with a peak Vo(2) of < 12 mL/kg/min had 5-fold, 8-fold, 5-fold, and 13-fold higher rates, respectively, of total cardiopulmonary complications pulmonary complications, cardiac complications, and mortality.

CONCLUSIONS

The present study supports a more liberal use of CPET before lung resection compared to the current guidelines since this test can help in stratifying the surgical risk and optimizing perioperative care.

Simulation of stent deployment in a realistic human coronary artery

Background

The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis.

Methods

3D reconstruction of a mildly stenosed coronary artery was carried out based on a combination of biplane angiography and intravascular ultrasound. Finite element method computations were performed to simulate the deployment of a stent inside the reconstructed coronary artery model at inflation pressure of 1.0 MPa. Strut thickness of the stent was varied to investigate stresses in the stent and the vessel wall.

Results

Deformed configurations, pressure-lumen area relationship and stress distribution in the arterial wall and stent struts were studied. The simulations show how the stent pushes the arterial wall towards the outside allowing the expansion of the occluded artery. Higher stresses in the arterial wall are present behind the stent struts and in regions where the arterial wall was thin. Values of 200 MPa for the peak stresses in the stent strut were detected near the connecting parts between the stent struts, and they were only just below the fatigue stress. Decreasing strut thickness might reduce arterial damage without increasing stresses in the struts significantly.

Conclusion

The method presented in this paper can be used to predict stresses in the stent struts and the vessel wall, and thus evaluate whether a specific stent design is optimal for a specific patient.

Performance at symptom-limited stair-climbing test is associated with increased cardiopulmonary complications, mortality, and costs after major lung resection

BACKGROUND

Exercise tests are increasingly used during preoperative evaluation before lung resection. This study assessed the association between performance at the symptom-limited stair-climbing test and postoperative cardiopulmonary morbidity, mortality, and costs after major lung resections.

METHODS

As part of their routine preoperative evaluation, 640 patients who had lobectomy (n = 533) or pneumonectomy (n = 107) for lung cancer from January 2000 through April 2007 performed a preoperative symptom-limited stair-climbing test. Sensitivity/specificity analysis was used to identify the best cutoff values of altitude climbed (number of steps x height of the step in m) associated with outcome. Univariate and multivariate regression analyses (validated by bootstrap) were used to test associations between preoperative and operative factors and postoperative cardiopulmonary complications, mortality, and postoperative costs.

RESULTS

The altitude reached at the stair-climbing test was reliably associated with increased cardiopulmonary complications (p = 0.04), mortality (p = 0.02), and costs (p < 0.0001). In patients who climbed less than 12 m, cardiopulmonary complications, mortality, and costs were 2-fold (p < 0.0001), 13-fold (p < 0.0001), and 2.5-fold higher, respectively, than in patients who climbed more than 22 m.

CONCLUSIONS

Performance at a maximal stair-climbing test was reliably associated with postoperative morbidity and mortality. We recommend the use of this simple and economic test in all lung resection candidates. Patients who perform poorly at the stair-climbing test should undergo a formal cardiopulmonary exercise test with measurement of oxygen consumption to optimize their perioperative management.

Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007

This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and interventional planning.

Modeling and mechanobiology of cerebral aneurysms

The purpose of this work is to review the computational models of the adaptive behavior of the cerebral vascular wall aimed at simulating aneurysm formation and enlargement. Cerebral aneurysms are localized abnormal enlargements of the intracranial arterial vessels. The origin of this pathology is still unclear: however, aneurysm formation is thought to be the result of interplay between biomechanical properties of the vessel wall and their possible changes, such as adaptive response to mechanical stimuli. Recently, different computational approaches were suggested in the literature aiming to describe the mechanobiology of the cerebral vascular wall. Most of the computational adaptive models showed a common approach for the geometrically non-linear kinematic description of the phenomenon, whilst the constitutive laws defining the rates of growth variables may differ considerably according to the specific phenomenon considered. These studies allowed the reproduction of some peculiar aspects of aneurysm mechanobiology; however, continued interdisciplinary research is mandatory for a better understanding of the mechanisms involved in the evolution of cerebral aneurysms.

A model to predict the immediate postoperative FEV1 following major lung resections

OBJECTIVE

FEV1 measured on the first postoperative day has shown to be a better predictor of complications than traditional ppoFEV1. Therefore, its estimation before operation may enhance risk stratification. The objective of this study was to develop and validate a model to predict FEV1 on the first postoperative day after major lung resection.

METHODS

FEV1 was prospectively measured on the first postoperative day in 272 patients submitted for lobectomy or pneumonectomy at two centers. A random sample of 136 patients was used to develop a model estimating the first day FEV1 by using multiple regression analysis including several preoperative and operative factors. The model was then validated by bootstrap analysis and tested on the other sample of 136 patients.

RESULTS

Factors reliably associated with postoperative first day FEV1 were age (p=0.002), preoperative FEV1 (p<0.0001), the presence of epidural analgesia (p<0.0001), and the percentage of non-obstructed segments removed during operation (p=0.001). The following model estimating the first day postoperative FEV1 was derived: -2.648+0.295 x age+0.371 x FEV1+8.216 x epidural analgesia - 0.338 x percentage of non-obstructed segments removed during operation. In the validation set, the mean predicted first day postoperative FEV1 value did not differ from the observed one (42.6 vs 42.0, respectively; p=0.3) and the plot of the observed versus the predicted first day FEV1 showed a satisfactory calibration.

CONCLUSIONS

We developed a model predicting the first day postoperative FEV1. If future analyses will prove its role in stratifying the early postoperative risk, it may be integrated in preoperative evaluation algorithms to refine risk stratification.

Quality of life before and after major lung resection for lung cancer: a prospective follow-up analysis

BACKGROUND

The objective of this study was to assess the preoperative and postoperative quality of life of candidates for major lung resection with lung cancer.

METHODS

In all, 156 consecutive patients (144 lobectomies, 12 pneumonectomies) were prospectively assessed by means of the Short Form-36 Health Survey, version 2, preoperatively and 1 month and 3 months after operation. Serial quality of life scales were compared by repeated measures analysis of variance.

RESULTS

In our series, most quality of life values were reduced compared with the general population. Compared with preoperative values, the physical composite scale was significantly reduced at 1 month (51 versus 45.1, p < 0.0001), and completely recovered at 3 months (51 versus 52.4, p = 0.2), whereas the mental composite scale remained unchanged. All correlation coefficients between these values and forced expiratory volume in 1 second, carbon monoxide lung diffusion capacity, and height reached at stair-climbing test at each evaluation period were below 0.2. With the exception of pneumonectomy patients (who had a significantly lower physical composite scale [p = 0.04]), no significant differences in both physical and mental values were noted in other high-risk subgroups of patients (elderly, coronary artery disease, poor pulmonary function) compared with lower-risk counterparts.

CONCLUSIONS

Candidates for lung resection with lung cancer had a worse preoperative quality of life compared with the general population. Quality-of-life measures had poor correlation with forced expiratory volume in 1 second, carbon monoxide lung diffusion capacity, and exercise test performance. Therefore, these functional variables cannot substitute for specific evaluation instruments. Finally, patients traditionally considered at higher risk for lung resection had postoperative physical and emotional quality of life scores similar to those observed in younger and fitter patients.

An axisymmetric computational model of skin expansion and growth

Skin expansion is the principal technique used in plastic surgery to repair large cutaneous defects, typically after tumour removal, burn care, craniofacial surgery and post-mastectomy breast reconstruction. It allows a gain of new tissue by means of gradual expansion of a prosthesis, surgically implanted beneath the patient's skin. Nevertheless, wide clinical use is not supported by a deep quantitative knowledge of the phenomena occurring during the expansion. A finite element model of the skin expansion was developed to evaluate the stresses and the strains of the skin due to the expander inflation and validated by proper in vitro experiments; furthermore, a growth model based on the mechanical stimulus was implemented to estimate the skin area gain. The developed computational approach, composed of the skin expansion model interaction and the growth law, proved its validity to investigate skin expansion phenomena: its use suggests a new predictive tool to optimize clinical procedures and the expander devices' design.

Computational fluid dynamics in a model of the total cavopulmonary connection reconstructed using magnetic resonance images

The recent developments in imaging techniques have created new opportunities to give an accurate description of the three-dimensional morphology of vessels. Such three-dimensional reconstruction of anatomical structures from medical images has achieved importance in several applications, such as the reconstruction of human bones, spine portions, and vascular districts.