A Machine Learning Approach for Postoperative Outcome Prediction: Surgical Data Science Application in a Thoracic Surgery Setting.

BACKGROUND: The use of innovative methodologies, such as Surgical Data Science (SDS), based on artificial intelligence (AI) could prove to be useful for extracting knowledge from clinical data overcoming limitations inherent in medical registries analysis. The aim of the study is to verify if the application of an AI analysis to our database could develop a model able to predict cardiopulmonary complications in patients submitted to lung resection. METHODS: We retrospectively analyzed data of patients submitted to lobectomy, bilobectomy, segmentectomy and pneumonectomy (January 2006-December 2018). Fifty preoperative characteristics were used for predicting the occurrence of cardiopulmonary complications. The prediction model was developed by training and testing a machine learning (ML) algorithm (XGBOOST) able to deal with registries characterized by missing data. We calculated the receiver operating characteristic curve, true positive rate (TPR), positive predictive value (PPV) and accuracy of the model. RESULTS: We analyzed 1360 patients (lobectomy: 80.7%, segmentectomy: 11.9%, bilobectomy 3.7%, pneumonectomy: 3.7%) and 23.3% of them experienced cardiopulmonary complications. XGBOOST algorithm generated a model able to predict complications with an area under the curve of 0.75, a TPR of 0.76, a PPV of 0.68. The model's accuracy was 0.70. The algorithm included all the variables in the model regardless of their completeness. CONCLUSIONS: Using SDS principles in thoracic surgery for the first time, we developed an ML model able to predict cardiopulmonary complications after lung resection based on 50 patient characteristics. The prediction was also possible even in the case of those patients for whom we had incomplete data. This model could improve the process of counseling and the perioperative management of lung resection candidates.

Computed tomography-guided microcoil placement for localizing small pulmonary nodules before uniportal video-assisted thoracoscopic resection.

PURPOSE: The increasing number of computed tomography (CT) performed allows the more frequent identification of small, solid pulmonary nodules or ground-glass opacities. Video-assisted thoracic surgery (VATS) represents the standard in most lung resections. However, since VATS limit is the digital palpation of the lung parenchyma, many techniques of nodule localization were developed. The aim of this study was to determine the feasibility and safety of CT-guided microcoil insertion followed by uniportal VATS wedge resection (WR). MATERIALS AND METHODS: Retrospective study in a single institution, including patients undergone CT-guided microcoil insertion prior to uniportal VATS resection between May 2015 and December 2018. The lesion was identified using fluoroscopy. RESULTS: Forty-six consecutive patients were enrolled (22 male and 24 female). On CT: 5 cases of GGO, 2 cases of semisolid nodules, 39 cases of solid nodules. The median pathologic tumor size was 1.21 cm. Neither conversion to thoracotomy nor microcoil dislodgement was recorded. All patients underwent uniportal VATS WR (9/46 underwent completion lobectomy after frozen section). WR median time was 105 min (range 50-150 min). No patients required intraoperative re-resection for positive margins. After radiological procedure, 1 case of hematoma and 2 cases of pneumothorax were recorded. Four complications occurred in the postoperative period. The mean duration of chest drain and length of stay were 2.9 and 4.6 days, respectively. CONCLUSIONS: CT-guided microcoil insertion followed by uniportal VATS resection was a safe and feasible procedure having a minimal associated complications rate and offering surgeons the ease of localization of small intrapulmonary nodules.

How the Pathological Microenvironment Affects the Behavior of Mesenchymal Stem Cells in the Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by fibroblasts activation, ECM accumulation, and diffused alveolar inflammation. The role of inflammation in IPF is still controversial and its involvement may follow nontraditional mechanisms. It is seen that a pathological microenvironment may affect cells, in particular mesenchymal stem cells (MSCs) that may be able to sustain the inflamed microenvironment and influence the surrounding cells. Here MSCs have been isolated from fibrotic (IPF-MSCs) and control (C-MSCs) lung tissue; first cells were characterized and compared by the expression of molecules related to ECM, inflammation, and other interdependent pathways such as hypoxia and oxidative stress. Subsequently, MSCs were co-cultured between them and with NHLF to test the effects of the cellular crosstalk. Results showed that pathological microenvironment modified the features of MSCs: IPF-MSCs, compared to C-MSCs, express higher level of molecules related to ECM, inflammation, oxidative stress, and hypoxia; notably, when co-cultured with C-MSCs and NHLF, IPF-MSCs are able to induce a pathological phenotype on the surrounding cell types. In conclusion, in IPF the pathological microenvironment affects MSCs that in turn can modulate the behavior of other cell types favoring the progression of IPF.

Uniportal Video-Assisted Thoracoscopic Surgery Completion Lobectomy Long after Wedge Resection or Segmentectomy in the Same Lobe: A Bicenter Study.

BACKGROUND: Completion lobectomy (CL) following a prior resection in the same lobe may be complicated by severe pleural or hilar adhesions. The role of uniportal video-assisted thoracoscopic surgery (U-VATS) has never been evaluated in this setting. METHODS: Data were collected from two Italian centers. Between 2015 and 2022, 122 patients (60 men and 62 women, median age 67.7 ± 8.913) underwent U-VATS CL at least 4 weeks after previous lung surgery. RESULTS: Twenty-eight (22.9%) patients were affected by chronic obstructive pulmonary disease (COPD) and twenty-five (20.4%) were active smokers. Among the cohort, the initial surgery was performed using U-VATS in 103 (84.4%) patients, triportal-VATS in 8 (6.6%), and thoracotomy in 11 (9.0%). Anatomical segmentectomy was the initial surgery in 46 (37.7%) patients, while hilar lymphadenectomy was performed in 16 (13.1%) cases. CL was performed on 110 (90.2%) patients, segmentectomy on 10 (8.2%), and completion pneumonectomy on 2 (1.6%). Upon reoperation, moderate pleural adhesions were observed in 38 (31.1%) patients, with 2 (1.6%) exhibiting strong adhesions. Moderate hilar adhesions were found in 18 (14.8%) patients and strong adhesions in 11 (9.0%). The median operative time was 203.93 ± 74.4 min. In four (3.3%) patients, PA taping was performed. One patient experienced intraoperative bleeding that did not require conversion to thoracotomy. Conversion to thoracotomy was necessary in three (2.5%) patients. The median postoperative drainage stay and postoperative hospital stay were 5.67 ± 4.44 and 5.52 ± 2.66 days, respectively. Postoperative complications occurred in 34 (27.9%) patients. Thirty-day mortality was null. Histology was the only factor found to negatively influence intraoperative outcomes (p = 0.000). Factors identified as negatively impacting postoperative outcomes at univariate analyses were male sex (p = 0.003), age > 60 years (p = 0.003), COPD (p = 0.014), previous thoracotomy (p = 0.000), previous S2 segmentectomy (p = 0.001), previous S8 segmentectomy (p = 0.008), and interval between operations > 5 weeks (p= 0.005). In multivariate analysis, only COPD confirmed its role as an independent risk factor for postoperative complications (HR: 5.12, 95% CI (1.07-24.50), p = 0.04). CONCLUSIONS: U-VATS CL seems feasible and safe after wedge resection and anatomical segmentectomy.

Impact of enhanced pathway of care in uniportal video-assisted thoracoscopic surgery.

Enhanced Recovery After Surgery (E.R.A.S.) is a multimodal, evidence-based and patient-centered pathway designed to minimize surgical stress, enhancing recovery and improving perioperative outcomes. However, considering that the potential clinical implication of E.R.A.S. on patients undergoing video-assisted thoracic surgery (V.A.T.S.) has not properly defined, we proposed to implement our minimally invasive program with a specific clinical pathway able to enhance recovery after lung resection. Aim of this study was to assess the impact of this integrated program of Enhanced Pathway of Care (E.P.C.) in Uniportal V.A.T.S. patients undergoing lung resection, in terms of efficiency and safety. We conducted a retrospective, observational study enrolling patients undergoing uniportal V.A.T.S. resections from January 2015 to May 2020. Two groups were created: pre-E.P.C. and E.P.C. Propensity score matching analysis was performed to evaluate length of stay (LOS), postoperative cardiopulmonary complications (CPC) and readmission rate (READM). We analyzed 1167 patients (E.P.C. group: 182; pre-E.P.C. group: 985). E.P.C. group has a mean LOS shorter compared to pre-E.P.C. group (3.13 vs 4.19 days, p < 0.0001) without increasing on CPC (E.P.C. 12% vs pre-E.P.C. 11%, p = 0.74) and READM rate (E.P.C. 1.6% vs pre-E.P.C. 4.9%, p = 0.07). In particular, the LOS was shortened in the E.P.C. patients submitted to lobectomy, segmentectomy and wedge resection. Moreover, the three subgroups had similar CPC and READM rates for E.P.C. and control patients. In conclusion, this study demonstrated the benefits and safety of E.P.C. program showing a reduction of LOS for patients undergoing uniportal V.A.T.S. resection.

Air leak and intraoperative bleeding in thoracic surgery: a Delphi consensus among the members of Italian society of thoracic surgery.

Background: Persistent air leak and the management of intraoperative blood loss are common threats in thoracic surgical practice. The availability of new procedures, technology and materials is constantly evolving topical hemostats and surgical sealants must be added to this toolkit. Topical hemostats and surgical sealants differ according to their chemical nature and physical characteristics, to their origin and mechanism of action, regulatory/registration and vigilance paths. A Delphi consensus was set to highlight the different points of view on the use of topical haemostatic products and sealants among the members of Italian Society of thoracic surgery. Methods: The board was formed by a group of five Italian experts; in the first phase after a careful review of the scientific literature and two rounds, the board finally generated 16 consensus statements for testing across a wider audience. During the second phase, the statements were collated into a questionnaire, which was electronically sent to a panel of 46 Italian surgeons, experts in the field. Results: Out of 46 Italian surgeons, 33 (72%) panel members responded to the Delphi questionnaire. All the items reached a positive consensus, with elevated levels of agreement, as demonstrated by the presence of a 100% consensus for nine items. For the remaining 7 statements the minimum level of consent was 88% (29 participants approved the statement and 4 disagreed) and the maximum was 97% (32 participants approved the statement and 1 was in disagreement). Conclusions: The present Delphi analysis shows that air leak and intraoperative bleeding are clinical problems well known among thoracic surgeons. Nevertheless, the aim of the scientific societies and of the group of experts is to execute the education activities in the surgery community. This Delphi survey suggest the need of wider and updated scientific information about technical and registration characteristics of most recent technologic solutions, such as the of topical hemostats and surgical sealants to provide healthcare and administrative staff with the opportunity to work and interact through a common and shared language and eventually to guarantee minimal requirements of assistance.

Peak oxygen consumption measured during the stair-climbing test in lung resection candidates.

BACKGROUND: The stair-climbing test is commonly used in the preoperative evaluation of lung resection candidates, but it is difficult to standardize and provides little physiologic information on the performance. OBJECTIVE: To verify the association between the altitude and the V(O2peak) measured during the stair-climbing test. METHODS: 109 consecutive candidates for lung resection performed a symptom-limited stair-climbing test with direct breath-by-breath measurement of V(O2peak) by a portable gas analyzer. Stepwise logistic regression and bootstrap analyses were used to verify the association of several perioperative variables with a V(O2peak) <15 ml/kg/min. Subsequently, multiple regression analysis was also performed to develop an equation to estimate V(O2peak) from stair-climbing parameters and other patient-related variables. RESULTS: 56% of patients climbing <14 m had a V(O2peak) <15 ml/kg/min, whereas 98% of those climbing >22 m had a V(O2peak) >15 ml/kg/min. The altitude reached at stair-climbing test resulted in the only significant predictor of a V(O2peak) <15 ml/kg/min after logistic regression analysis. Multiple regression analysis yielded an equation to estimate V(O2peak) factoring altitude (p < 0.0001), speed of ascent (p = 0.005) and body mass index (p = 0.0008). CONCLUSIONS: There was an association between altitude and V(O2peak) measured during the stair-climbing test. Most of the patients climbing more than 22 m are able to generate high values of V(O2peak) and can proceed to surgery without any additional tests. All others need to be referred for a formal cardiopulmonary exercise test. In addition, we were able to generate an equation to estimate V(O2peak), which could assist in streamlining the preoperative workup and could be used across different settings to standardize this test.

Uniportal video-assisted thoracoscopic left superior segmentectomy.

Obtaining adequate margins when performing lung cancer resection is crucially important. Therefore, during thoracoscopic segmentectomy, where the direct palpation of the tumor is not always possible, it is mandatory to accurately identify the intersegmental plane in order to achieve a satisfactory oncological and surgical result. In this video tutorial, we demonstrate a uniportal video-assisted thoracoscopic (VATS) superior segmentectomy of the left lower lobe, adopting two different techniques for identifying the intersegmental plane: the inflation-deflation method and selective resected segmental inflation, and we present the pros and cons of each. With the inflation/deflation technique, which is the most common maneuver used, we inflated the whole lung after occlusion of the target segmental bronchus, inducing collapse of the superior segment and inflation of the remaining lobe. However, this inexpensive and easy method often makes identification of the intersegmental plane unreliable because of the collateral ventilation. Moreover, because of the expansion of inflated segments, it limits thoracic working space during the VATS procedure. In contrast, selective resected segmental inflation guarantees an optimal surgical space even during a VATS procedure. In this case, we directly inflated the segmental bronchus of the superior segment through a butterfly needle in order to selectively expand only the selected segment. The careful demarcation of the intersegmental plane is mandatory in order to obtain adequate margins and achieve a high success rate for thoracoscopic segmentectomy. Although a one-size-fits-all method is not feasible, we strongly recommend  making every effort for identifying it as best as possible; indeed, its inadequate demarcation may be the main cause of unsatisfactory surgical and oncological results in terms of locoregional recurrence and long-term survival.

Uniportal video-assisted thoracoscopic thymectomy: the glove-port with carbon dioxide insufflation.

BACKGROUND: Since 2004, uniportal video-assisted thoracic surgery (VATS) approach was progressively widespread and also applied in the treatment of thymoma, with promising results. We report the first series of patients who undergone uniportal VATS thymectomy using a homemade glove-port with carbon dioxide (CO2) insufflation. The aim of this article is to analyze the safety and feasibility to perform an extended thymectomy (ET). METHODS: A prospective, single-centre, short-term observational study including patients with mediastinal tumours undergoing scheduled uniportal VATS resection using a glove-port with CO2. Operations were performed through a single incision of 3.5 cm at the fifth intercostal space, right or left anterior axillary line. A 5 mm-30° camera and working instruments were employed through a glove-port with CO2. RESULTS: Thirty-eight patients (20 men; mean age 61.6 years) underwent ET between September 2016 and October 2019. Thirteen patients had a history of Myasthenia Gravis (MG) with thymoma and 8 had incidental findings of thymoma. Additionally, 8 mediastinal cysts and 9 thymic hyperplasia were included. Mean diameter of the tumor was 5.1 cm (range, 1.6-14 cm) and mean operation time was 143 minutes. Mean postoperative drainage duration and hospital stay were 2.3 and 4.3 days, respectively. Mean blood loss was 41 mL. There was no occurrence of surgical morbidity or mortality. During the follow-up period (1-36 months), no recurrence was noted. CONCLUSIONS: Our results suggest that uniportal VATS thymectomy through glove-port and CO2 is safe and feasible procedure, even with large thymomas. Furthermore, the glove-port system represents a valid, cheap and widely available alternative to the commercial devices usually adopted in thoracic surgery.

The role of angiogenetic single-nucleotide polymorphisms in thymic malignancies and thymic benign lesions.

BACKGROUND: We previously showed that selected single-nucleotide-polymorphisms (SNPs) of genes involved in angiogenesis influence the aggressiveness of thymic epithelial tumors (TETs). This study analyzes their role in TETs and in thymic benign lesions, in order to investigate potential correlation with risk and outcome. METHODS: Genomic DNA was extracted from paraffin-embedded tissue of 92 patients, undergoing surgery at our Institution. We investigated by Real-Time PCR the SNPs of the following genes: platelet-derived growth factor receptor-α (PDGFRα), hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGF-A), vascular endothelial growth factor receptor-2 and 3 (VEGF-2, VEGFR-3), excision repair cross-complementation group-1 (ERCC1). RESULTS: Fifty-seven TETs and 35 thymic benign lesions were included into the study. Frequency of SNPs was as follows: rs2057482 C, rs11158358 C and rs11549465 C polymorphisms of HIF1-a: thymomas < general population (P=0.008, P=0.007, and P=0.044 respectively). HIF1-a alleles: general population > study groups, rs1951795C SNP (P=0.026 for benign lesions and P=0.0007 for thymomas), rs10873142T SNP (P=0.008 and P=0.001 respectively), rs12434438 A SNP (P=0.034 and P=0.0007) and rs2301113A SNP (P=0.027 and P=0.010). rs699947C polymorphism of VEGF-A: benign lesions > general population (P=0.012). CONCLUSIONS: This is the first study investigating the angiogenetic polymorphisms in thymic benign lesions and TETs. SNPs analysis may represent a further asset in identification of patients who could benefit from anti-angiogenetic therapy.

Prognostic relevance of programmed cell death protein 1/programmed death-ligand 1 pathway in thymic malignancies with combined immunohistochemical and biomolecular approach.

BACKGROUND: The aim of the study was to investigate Programmed cell Death protein 1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) and their mRNA expression in thymic epithelial tumors (TETs). RESEARCH DESIGN AND METHODS: We analyzed 68 samples of formalin-fixed paraffin-embedded tissue (63 thymomas and 5 thymic carcinomas). PD-1 and PD-L1 protein expression were evaluated by immunohistochemistry, and mRNA expression was evaluated by real-time PCR. RESULTS: M/F ratio was 33/35, and median age was 60.5 years. Twenty patients had Myasthenia Gravis (MG). In the subgroup with large tumors (>5 cm), PD-L1 mRNA overexpression was significantly associated with worse prognosis vs. patients with no mRNA overexpression (p = 0.0083) and simultaneous PD-L1 immunostaining (>1%); PD-L1 mRNA overexpression was significantly associated with worse prognosis, respect to patient with PD-L1 negative immunostaining, and no PD-L1 mRNA overexpression (p = 0.0178). The elderly patients (>60 years) with large tumors showed worse prognosis (p = 0.0395). PD-L1 immunostaining (>50%) resulted to be significantly associated with MG. CONCLUSIONS: Our data suggest the potential involvement of the PD-1 and PD-L1 pathway in TETs' progression. According to our results, it may be helpful to design future trials with anti-PD-1 drugs to establish high-risk patients after surgery.

Chest wall lipoma mimicking intrathoracic mass: Imaging with surgical correlation.

Lipoma is the most frequent benign soft-tissue tumor. It originates from fat cells. According to position, it is distinguished in superficial, typically subcutaneous lipoma, or deep, such as intramuscular lipoma. This latter form is infrequently and may resemble well-differentiated liposarcoma. For this reason, early radiological detection and characterization are necessary to obtain a wide complete resection and histopathologic evaluation to differentiate benign from malign lesions. We report an extremely rare case of an intrathoracic intramuscular lipoma of the chest wall detect and characterize with chest X-ray and computed tomography examinations, resected with thoracoscopic intervention and confirmed with histopathologic analysis.

Oxygen desaturation during maximal stair-climbing test and postoperative complications after major lung resections.

OBJECTIVE: Non-univocal conclusions have been published regarding the definition of oxygen desaturation in relation to postoperative outcome. We aimed to verify whether oxygen desaturation during a maximal stair-climbing test was associated with postoperative cardiopulmonary complications and to assess which definition of oxygen desaturation (oxygen saturation <90% or desaturation >4% with respect to rest level) discriminated better between complicated and uncomplicated patients. METHODS: Five hundred and thirty-six patients performing a maximal stair-climbing test prior to major lung resection were analyzed. All patients performed the test on room air. Patients with and without cardiopulmonary complications were compared in terms of several preoperative and operative characteristics by univariate analysis, including the presence of oxygen desaturation at peak exercise (saturation <90% or desaturation >4%). Logistic regression analysis was then performed and validated by bootstrap procedure to identify predictors of complications and to see whether the exercise oxygen desaturation retained its significancy after multivariable adjustment. RESULTS: Twenty-seven patients had an exercise oxygen saturation below 90%, but this parameter was not significantly associated with complications. Seventy-five patients experienced an exercise desaturation greater than 4%, which was a significant result associated with postoperative complications at univariate analysis (p=0.008) (36% complication rate). After adjusting for age, ppoFEV1, ppoDLCO, type of operation, height reached at stair-climbing test and cardiac co-morbidity, a desaturation greater than 4% retained its significance at logistic regression and proved to be stable at bootstrap. CONCLUSIONS: A stair-climbing test is an intense constant workload exercise, challenging a large amount of muscle mass, and appears particularly appropriate to elicit oxygen desaturation, which in turn may be a reliable marker of deficits in the oxygen transport system. A desaturation >4% appears a better cut-off definition than a saturation level <90% in predicting the occurrence of complications. The risk of complications was approximately two-fold higher in patients with oxygen desaturation >4% at peak exercise.

Enhanced recovery after thoracic surgery: patient information and care-plans.

Many studies have confirmed that the implementation of enhanced recovery after surgery (ERAS) protocols has the advantages of reducing the potential complications after thoracic surgery and the length of hospital stay. The ERAS program involves a multidisciplinary team, aimed at integrating evidence-based knowledge into clinical practice in order to reduce the patient's stress response to the surgical procedure and improve the response to stress, guaranteeing a combination of better outcomes and cost savings. All this would not be possible without the improvement of minimally invasive surgical techniques, progression of anesthesia, pain control, and careful patient preparation. In this setting, a preoperative personal counselling may play a key role to reduce stress, fear or anxiety and improve the morbidity of patients, enabling them to achieve functional and psychological compensatory mechanisms more quickly. Preoperative patient counselling, performed using verbal, written or multimedia materials, is crucial in order to achieve the goal of the ERAS project: making the patient a potentially active participant and the main character of his recovery, able to positively impact himself throughout the surgical and healing process. This report is aimed at evaluating patient information and care-plans in thoracic surgery, reviewing the available evidence on ERAS pathways, and demonstrating our ideal program as discussed and shared among the Italian Thoracic Surgery Units accredited in the video-assisted thoracic surgery (VATS) group.

Evaluation of expiratory volume, diffusion capacity, and exercise tolerance following major lung resection: a prospective follow-up analysis.

BACKGROUND: Lung resections determine a variable functional reduction depending on the extent of the resection and the time elapsed from the operation. The objectives of this study were to prospectively investigate the postoperative changes in FEV(1), carbon monoxide lung diffusion capacity (Dlco), and exercise tolerance after major lung resection at repeated evaluation times. METHODS: FEV(1), Dlco, and peak oxygen consumption (Vo(2)peak) calculated using the stair climbing test were measured in 200 patients preoperatively, at discharge, and 1 month and 3 months after lobectomy or pneumonectomy. Preoperative and repeated postoperative measures were compared, and a time-series, cross-sectional regression analysis was performed to identify factors associated with postoperative Vo(2)peak. RESULTS: One month after lobectomy, FEV(1), Dlco, and Vo(2)peak values were 79.5%, 81.5%, and 96% of preoperative values and recovered up to 84%, 88.5%, and 97% after 3 months, respectively. One month after pneumonectomy, FEV(1) percentage of predicted, Dlco percentage of predicted, and Vo(2)peak values were 65%, 75%, and 87% of preoperative values, and were 66%, 80%, and 89% after 3 months, respectively. Three months after lobectomy, 27% of patients with COPD had improved FEV(1), 34% had improved Dlco, and 43% had improved Vo(2)peak compared to preoperative values. The time-series, cross-sectional regression analysis showed that postoperative Vo(2)peak values were directly associated with preoperative values of Vo(2)peak, and postoperative values of FEV(1) and Dlco, and were inversely associated with age and body mass index. CONCLUSIONS: Our findings may be used during preoperative counseling and for deciding eligibility for operation along with other more traditional measures of outcome.

Measured FEV1 in the first postoperative day, and not ppoFEV1, is the best predictor of cardio-respiratory morbidity after lung resection.

INTRODUCTION AND OBJECTIVE: There is a low correlation between predicted postoperative FEV1 (ppoFEV1) and FEV1 measured the days after pulmonary resection, when most complications are developed. The hypothesis of this investigation is that ppoFEV1 does not predict postoperative morbidity in patients undergoing lung resection when immediate postoperative FEV1 is considered in the predictive model. METHODS: One hundred ninety-eight consecutive patients undergoing lobectomy or pneumonectomy were included in a prospective, multiinstitutional study. INDEPENDENT VARIABLES: age, body mass index, ppoFEV1, surgical approach (VATS or muscle-sparing thoracotomy), type of analgesia (epidural or intraveous), postoperative visual analogue pain score and FEV1 measured the day after the operation. Target variable: occurrence of postoperative cardio-respiratory complications. Method of analysis: classification tree (CART) dividing the population at random in two subsets and developing a bootstrap set of 100 trees resampling training data. The relative importance of each variable and the accuracy of both initial and committee trees to predict the outcome were presented. RESULTS: One hundred seventy-seven lobectomies and 21 pneumonectomies were included. Overall cardio-respiratory morbidity was 22%. According to CART results, first day FEV1 was the most important variable to classify cases as primary splitter and as a surrogate of each primary splitter (100% importance). Patient age followed (51%) and ppoFEV1 was third (43%) with a score similar to postoperative pain score (42%) and type of analgesia (36%). Sensitivity and specificity of the initial tree were, respectively, 0.5 and 0.7; values for committee tree were 0.5 sensitivity and 0.7 specificity. CONCLUSION: Postoperative cardio-respiratory complications are more related to FEV1 measured in the first postoperative day than to ppoFEV1 value.

Physiopathology aspects of anatomical video-assisted thoracic surgery resections: current status and prospects of development.

Pulmonary lobectomy remains the gold standard therapy for early-stage lung cancer. With the spread of video-assisted thoracic surgery (VATS), surgeons began using this approach also to perform lobectomies, becoming progressively widespread worldwide. However some early-stage lung cancer patients are of questionable eligibility for open lobectomy being considered at high-risk to develop postoperative complications due to compromised pulmonary function or cardiopulmonary reserve. Herein we evaluate pathophysiology of VATS, focusing on: the correlation between the traditional predictors of outcome and overall complications, the current status of different VATS approaches and the role of VATS segmentectomy in high-risk patients, unable to tolerate lobectomy for their compromised cardiopulmonary reserve.

Video-assisted thoracic surgery lobectomy does not offer any functional recovery advantage in comparison to the open approach 3 months after the operation: a case matched analysis†.

OBJECTIVES: The objective of the present study was to compare functional loss [forced expiratory volume in one second to forced vital capacity ratio (FEV1), DLCO and VO2max reduction] after VATS versus open lobectomies. METHODS: We performed a prospective observational study on 195 patients who had a pulmonary lobectomy from June 2010 to November 2014 and who were able to complete a 3-months functional evaluation follow-up program. Since the VATS technique was our first choice for performing lobectomies from January 2012, we divided the patients into two groups: the OPEN group (112 patients) and the VATS group (83 patients). The open approach was intended as a muscle sparing/nerve sparing lateral thoracotomy. Fourteen baseline factors were used to construct a propensity score to match the VATS-group patients with their OPEN-group counterparts. These two matched groups were then compared in terms of reduction of FEV1, DLCO and VO2max (Mann-Whitney test). RESULTS: The propensity score analysis yielded 83 well-matched pairs of OPEN and VATS patients. In both groups, 3 months postoperatively, we found a reduction in FEV1, DLCO and VO2max values (OPEN patients: FEV1-10%, DLCO -11.9%, VO2max - 5.5%; VATS patients: FEV1-7.2%, DLCO-10.6%, VO2max-6.9%). The reductions in FEV1, DLCO and VO2max were similar to those in the two matched groups, with a Cohen effect size <0.2 for all the comparisons. CONCLUSIONS: In 3 months, both OPEN patients and VATS patients experienced a reduction in their preoperative functional parameters. VATS lobectomy does not offer any advantages in terms of FEV1, DLCO and exercise capacity recovery in comparison to the muscle-sparing thoracotomy approach.

Air leaks after lobectomy increase the risk of empyema but not of cardiopulmonary complications: a case-matched analysis.

PURPOSE: To assess whether the presence and duration of air leaks after lobectomy are associated with an increased incidence of cardiopulmonary complications. METHODS: Propensity score analysis was used on 726 patients undergoing pulmonary lobectomy from 1995 through 2004 to form three well-matched pairs of patients: patients with prolonged air leak (PAL) [> 7 days] and without air leak; patients with short air leak (SAL) [< or = 7 days] and without air leak; and patients with SAL and PAL. These matched groups were then compared to assess postoperative hospital stay and early outcome. RESULTS: Patients with SAL had a longer postoperative hospital stay compared to patients without air leak (8.6 days vs 7.8 days, respectively; p < 0.0001) but had similar morbidity and mortality. Patients with PAL had a longer postoperative hospital stay compared to patients without air leak (16.2 days vs 8.3 days, respectively; p < 0.0001) and with SAL (16.9 days vs 9 days, respectively; p < 0.0001), but similar cardiopulmonary complications were noted between the groups. Patients with PAL had a higher rate of empyema compared to patients without air leak and with SAL (8.2% vs 0%, p = 0.01 and 10.4% vs.1.1%, p = 0.01, respectively). CONCLUSIONS: The presence of air leak was not associated with an increased incidence of cardiopulmonary morbidity but was associated with an increased risk of empyema. Future prospective studies are needed to confirm safety of fast track in patients with air leak.

Carbon monoxide lung diffusion capacity improves risk stratification in patients without airflow limitation: evidence for systematic measurement before lung resection.

OBJECTIVE: In many centers, carbon monoxide lung diffusion capacity (DLCO) is still not routinely measured in all patients but only in patients with airflow limitation. The objective of the study was to assess the degree of correlation between forced expiratory volume in 1s (FEV1) and DLCO, and verify whether a low predicted postoperative DLCO (ppoDLCO) could have a role in predicting complications in patients without airflow limitation. METHODS: We analyzed 872 patients submitted to lung resection between January 2000 and December 2004 in two units measuring systematically DLCO before operation. Correlation between FEV1 and DLCO was assessed in the entire dataset and in different subsets of patients. A number of variables were then tested for a possible association with postoperative cardiopulmonary complications in patients with FEV1>80% by univariate analysis. Variables with p<0.10 at univariate analysis were used as independent variables in a stepwise logistic regression analysis (dependent variable: presence of cardiopulmonary morbidity), which was in turn validated by bootstrap analysis. RESULTS: The correlation coefficients between FEV1 and DLCO in the entire dataset and in different subsets of lung resection candidates (stratified by age, gender, cause of operation, airflow limitation) were all below 0.5, showing a modest degree of correlation. Two hundred and nineteen of the 508 patients (43%) with FEV1>80% had DLCO<80%. Moreover, in patients with FEV1>80%, logistic regression analysis showed that ppoDLCO<40% was a significant and reliable predictor of postoperative complications (p=0.004). CONCLUSION: The modest correlation between FEV1 and DLCO and the capacity of ppoDLCO to discriminate between patients with and without complications in subjects with a normal FEV1, warrants the routine measurement of DLCO in all candidates for lung resection, irrespective of their FEV1 value, in order to improve surgical risk stratification.