Outcomes after Conversion from Video-Assisted Thoracoscopic Lobectomy to Thoracotomy.

BACKGROUND: Lung cancer resections are increasingly being performed via video-assisted thoracoscopic surgery (VATS). Conversion to thoracotomy can occur for many reasons and may affect outcomes. The objective of this study was to investigate the impact of VATS conversion on short- and mid-term outcomes and identify reasons for conversion. METHODS: Consecutive patients undergoing lobectomy for primary non-small cell lung cancer between 2012 and 2019 in a single UK center were included. Primary outcomes were 90-day mortality, intraoperative conversion, and overall survival. Reasons for conversion were defined as bleeding or nonbleeding. Outcomes were compared between groups using univariable analysis. Multivariable logistic regression analysis was performed to identify risk factors for conversion. RESULTS: A total of 2,622 patients were included with 20.6% (n = 541) completing surgery via VATS and 79.4% (n = 2,081) via thoracotomy. The rate of completed VATS surgery increased significantly over time (2012: 6.9%, 2019: 55.1%, p < 0.001). Overall conversion rate was 14.3% (n = 90/631) and has reduced significantly over time (p < 0.001). The rate of conversion due to intraoperative bleeding was 31.1% (n = 28/90). Obesity, male sex, and stage III disease were independent risk factors for conversion. The 90-day mortality rate after conversion was not significantly different from the rate for planned thoracotomy (3.3 vs. 3.4%, p = 0.987). There was no significant difference in overall survival between patients experiencing intraoperative conversion and those undergoing planned thoracotomy (p = 0.135). CONCLUSION: This study demonstrates comparable outcomes for patients undergoing conversion from VATS to those undergoing planned surgery via thoracotomy. It remains unclear if reason for conversion is associated with outcomes.

Adequacy of Mediastinal Lymph Node Sampling in Patients With Lung Cancer Undergoing Lung Resection.

BACKGROUND: Intraoperative mediastinal lymph node sampling (MLNS) is a crucial component of lung cancer surgery. Whilst several sampling strategies have been clearly defined in guidelines from international organizations, reports of adherence to these guidelines are lacking. We aimed to assess our center's adherence to guidelines and determine whether adequacy of sampling is associated with survival. MATERIALS AND METHODS: A single-center retrospective review of consecutive patients undergoing lung resection for primary lung cancer between January 2013 and December 2018 was undertaken. Sampling adequacy was assessed against standards outlined in the International Association for the Study of Lung Cancer 2009 guidelines. Multivariable logistic and Cox proportional hazards regression analyses were used to assess the impact of specific variables on adequacy and of specific variables on overall survival, respectively. RESULTS: A total of 2380 patients were included in the study. Overall adequacy was 72.1% (n= 1717). Adherence improved from 44.8% in 2013 to 85.0% in 2018 (P< 0.001). Undergoing a right-sided resection increased the odds of adequate MLNS on multivariable logistic regression (odds ratio 1.666, 95% confidence interval [CI]: 1.385-2.003, P< 0.001). Inadequate MLNS was not significantly associated with reduced overall survival on log rank analysis (P= 0.340) or after adjustment with multivariable Cox proportional hazards (hazard ratio 0.839, 95% CI 0.643-1.093). CONCLUSIONS: Adherence to standards improved significantly over time and was significantly higher for right-sided resections. We found no evidence of an association between adequate MLNS and overall survival in this cohort. A pressing need remains for the introduction of national guidelines defining acceptable performance.

Case Report: Spontaneous lung intercostal hernia series and literature review.

Spontaneous lung intercostal hernia (SLIH) is a rare condition potentially carrying severe morbidity. About 120 cases have been described so far, with an apparently increasing number of reports in recent years. The main presenting findings are chest pain and bulging, with ecchymosis in the affected area, hemoptysis, respiratory distress, and signs of infection or incarceration being described as well. The gold standard treatment has not been established, and conservative management has been advocated as first-line treatment for asymptomatic patients. Here, we report a case series of five patients, and surgical repair was deemed necessary for four of them either at first evaluation or after failure of conservative management. One patient remains under surveillance and conservative management. We believe that SLIH surgical repair should be considered as first-line treatment for fit patients, due to the uncertainty of its mid- and long-term impact and described pejorative trend/defect enlargement. A proposed algorithm for SLIH management is also presented.

Comparison of traditional microbiological culture and 16S polymerase chain reaction analyses for identification of preoperative airway colonization for patients undergoing lung resection.

PURPOSE: Preoperative airway colonization is associated with increased risk of postoperative respiratory complications following lung resection. This study compares the rates of preoperative lower respiratory tract colonization identified by traditional culture and novel 16S polymerase chain reaction (PCR) tests. MATERIALS AND METHODS: Preoperative sputum and bronchoalveolar lavage (BAL) samples for 49 lung resection patients underwent culture and 16S PCR analyses. Rates of positive test results were determined and relationships between test results and suspected postoperative respiratory tract infection and hospital length of stay (LOS) were investigated. RESULTS: Preoperative BAL cultures were positive for 29 (59.2%) patients (population estimate 95%CI 45.2%-71.8%). 16S PCR tests were positive for 28 (57.1%) patients (population estimate 95%CI 43.3%-70.0%). 17 (34.7%) patients suffered suspected postoperative respiratory tract infection (population estimate 95%CI 22.9%-48.7%). Positive 16S PCR results tended to be associated with longer LOS (median 7.5 days vs 4.0 days for negative, p = 0.08) and increased risk of suspected postoperative respiratory tract infection (46.4% for positive vs 19.0% for negative, p = 0.07). CONCLUSIONS: Rates of colonization identified by culture and 16S PCR analyses of BAL samples were similar. Future research should attempt to clarify associations between airway colonization identified by 16S PCR and outcomes. 16S PCR may be useful when stratifying risk of postoperative respiratory complications.

Prevalence of nodal metastases in lymph node stations 8 & 9 in a large UK lung cancer surgical centre without routine pre-operative EUS nodal staging.

INTRODUCTION: Endoscopic ultrasound (EUS) allows access to the inferior mediastinal lymph node stations (8 and 9) which are beyond the reach of endobronchial ultrasound (EBUS). The addition of EUS to EBUS procedures requires cost and resource investment. This study sought to describe the prevalence of station 8/9 nodal metastases from intra-operative lymph node sampling in a UK region where routine pre-operative EUS is not available. METHODS: A retrospective review of all lung cancer resections at the University Hospital South Manchester from 2011 to 2014. Surgical variables, pre-operative PET variables and survival outcomes were collected and analysed. RESULTS: 1421 surgical resections were performed in the study period. Lymph node stations 8 and/or 9 were sampled in 52% (736/1421) of patients. Overall, there were 34 patients with lymph node metastases at station 8/9. This represents 2.4% of the study populations and 4.6% of patients in whom stations 8/9 were sampled intra-operatively. Of those patients with station 8/9 metastases, 65% (22/34) had multi-station N2 disease and the majority of the additional N2 disease was present in EBUS-accessible areas (lymph node stations 2, 4 and 7). Two percent (16/736) of patients in whom station 8/9 lymph nodes were sampled intra-operatively had N2 disease that was only accessible endoscopically with EUS. There was no significant difference in overall survival in patients with pathological N2 disease stratified according to whether stations 8/9 were involved or not. CONCLUSIONS: The prevalence of lymph node metastases in stations 8/9 in this UK surgical centre where routine pre-operative EUS is not performed is low at approximately 5%. Given the identification of N2 disease in two-thirds of these patients can potentially be achieved through EBUS alone, this questions whether the resource implications of EUS are justified by the impact on patient management.

Adequacy of Intraoperative Nodal Staging during Surgical Resection of NSCLC: Influencing Factors and Its Relationship to Survival.

INTRODUCTION: Adequate intraoperative lymph node sampling is a fundamental part of lung cancer surgery, but adherence to standards is not well known. This study sought to measure the adequacy of intraoperative lymph node sampling at a regional Thoracic Surgery Centre and a tertiary lung cancer center in the United Kingdom. METHODS: This retrospective study analyzed the pathological reports from NSCLC resections over the 4-year period 2011-2014. Adequacy of sampling was assessed against International Association for the Study of Lung Cancer recommendations of at least three mediastinal lymph node stations: station 7 in all patients, station 5 or 6 in left upper lobe tumors, and station 9 in lower lobe tumors. The influence of clinical variables (age, tumor T stage, type of surgery, and laterality) on adequacy of sampling and the effect of adequacy on overall survival were also assessed. RESULTS: A total of 1301 NSCLC resections were performed from January 11, 2011, to December 31, 2014. Adequate intraoperative lymph node sampling increased significantly from 14% (22 of 160) in 2011 to 53% (206 of 390) in 2014 (p = 0.001). Secondary analysis of clinical variables also revealed that patients with T1a or T4 tumors, those undergoing sublobar resections, those undergoing video-assisted thoracic surgery resections, and those undergoing left-sided resections have significantly higher rates of inadequate lymph node sampling. Overall, there was no statistically significant difference in survival between patients with adequate versus inadequate intraoperative lymph node sampling or when survival was stratified according to overall stage. There was worse survival in inadequate sampling for patients with pN2 disease than for patients with pN2 disease and adequate sampling. CONCLUSION: This study provides a much-needed benchmark of current thoracic surgical practice in lung cancer in the United Kingdom and important granularity to facilitate changes to improve adequacy of staging.

Is there a role for the high-risk multidisciplinary team meeting in thoracic surgery?

OBJECTIVES: There is little information on the impact of a high-risk multidisciplinary team (HRMDT) for thoracic surgery. In our unit, patients considered high risk for thoracic surgery have been discussed at this meeting since its inception in June 2013. The aim of this study was to audit our selection of patients discussed at the HRMDT and its effect on patient outcomes. METHODS: Data were prospectively collected on all patients (n = 820) who underwent lung resection for lung cancer between July 2013 and September 2014. Patients were analysed as two groups HRMDT versus non-HRMDT. Referral to the HRMDT was at the operating surgeons' discretion. Referred patients usually had a higher-than-expected mortality or morbidity risk for the indicated procedure. The median time from HRMDT to surgery was 27 days (IQR 27.75). The median follow-up for all patients was 415 days (IQR 240). RESULTS: There were 102 patients in the HRMDT group and 718 in the non-HRMDT group (males 54 vs 46%; P = 0.12). The median duration from HRMDT to surgery was 27 days (IQR 27.75). Mean age (P = 0.0001), cardiac risk score (P = 0.001) and Thoracoscore (P = 0.0001) were significantly higher in the HRMDT group. There was also a significantly higher proportion of pneumonectomies in the HRMDT group (12 vs 4%; P = 0.001). There were no significant differences between the groups in cardiac, cerebrovascular, GI, pulmonary, renal or composite complications. There was no significant difference in 30-day (3 vs 1%; P = 0.24) or 90-day (5 vs 3%; P = 0.48) mortality between the groups. Operated HRMDT patients had better survival at 200 days (P = 0.002), but there was no difference in long-term survival compared with patients turned down for surgery. CONCLUSIONS: Despite a higher predicted mortality rate by Thoracoscore, HRMDT patients had the same outcome as lower risk non-HRMDT patients. Within the HRMDT cohort, survival in the operated patients was significantly better than that in non-operated patients in the short term. The HRMDT has managed to offer patients a radical treatment option who might have been refused surgery prior to this due to their higher risk profile. We would recommend this forum as a means to further assess and discuss high-risk patients.

Should we operate on microscopic N2 non-small cell lung cancer?

Traditionally non-small cell lung cancer (NSCLC) stage N2 is considered as a contraindication for curative resection. We investigated the outcome of patients with microscopic N2 disease, who underwent potentially curative resections. The independent effects of lobectomy vs. pneumonectomy, histology subtype, body mass index (BMI), sex, and PET-scanning were investigated. An N2 survival risk score was calculated and correlated with survival. Benchmarking revealed no discrepancies in our stage-specific survival data against the seventh edition of the International Association for the Study of Lung Cancer (IASLC) results. Of 1999 lung resections for primary lung cancer, 146 were pathologically staged as N2. Patients with resected microscopic N2 disease had a five-year survival equivalent to stage T3N1, P=0.39. Univariate analysis suggested pneumonectomy and T stage 3 as significant predictors of poor survival. Cox multivariate regression analysis revealed that age, BMI>30 kg/m(2), pneumonectomy, squamous type and positron emission tomography (PET)-scan all had a significant effect on survival, P<0.05. A low N2 survival risk score was associated with increased survival, P=0.001. Resecting microscopic N2 disease in NSCLC may be appropriate in some patients. An N2 survival scoring system may help select patients for surgery, and help evaluate adjuvant and neoadjuvant publications with regard to microscopic N2 disease.

Does positron emission tomography scanning improve survival in patients undergoing potentially curative lung resections for non-small-cell lung cancer?

OBJECTIVE: To determine if positron emission tomography (PET) scanning has resulted in an improvement in the short- and long-term survival of patients undergoing potentially curative resections for non-small-cell lung cancer. No publications exist to demonstrate an increased survival of patients with lung cancer due to the use of PET scanning. If PET scanning reduces unnecessary resections, the results from surgery should be improved with its introduction. METHODS: A prospective thoracic surgery database was retrospectively analysed. Patients (N=1999), who had undergone potentially curative resections for non-small-cell lung cancer, and those who had a PET scan pre operatively (N=934), were compared with patients who had not undergone PET scanning (N=1065), prior to surgical resection. PET scanning became routine for all patients 4 years ago in our unit. Staging was defined as pathological staging to eliminate bias by 'better' preoperative staging due multislice computed tomography (CT) and PET scanning. Propensity matching based on Cox regression analysis was performed for survival analysis at each stage. RESULTS: Propensity matching revealed that the introduction of routine PET scanning did not result in improved survival in the short or long term, for patients undergoing resections for stage Ia (N=271 in each matched group), p=0.74, stage Ib (N=321 in each matched group), p=0.43 and stage II (N=164 in each matched group), p=0.06. PET has however resulted in a significant increased survival for patients undergoing resections for stage III primary lung cancer (N=68 in each matched group), p=0.03. CONCLUSION: We concur with current guidelines for the use of PET scanning for stage III non-small-cell lung cancer. Our results need to be corroborated with other groups as potentially stage-Ia-, Ib-, and stage-II patients may not benefit from PET scanning.

Aspirin and non-small cell lung cancer resections: effect on long-term survival.

OBJECTIVE: Survival after resections for non-small cell lung cancer remains poor. Recurrent lung cancer remains common. Due to the common risk factor of smoking, cardiovascular deaths occur in the absence of recurrent lung cancer in up to 15% of patients. Aspirin has been proven to reduce cardiovascular mortality as a secondary prophylactic agent, but not as a primary agent. Aspirin being a COX-2 inhibitor has been shown to reduce the chance of metastasis in adenocarcinoma but not squamous carcinoma. We sought to investigate the effect of long-term aspirin therapy on survival post potentially curative surgery. METHODS: We analysed a prospective thoracic surgical database, from time period 2003 to date. Patients who were on aspirin pre-operatively, N=412 were compared to non users, N=1353. Patient long-term outcome was assessed utilising the national strategic tracking service that operates in the United Kingdom. Cox proportional hazards analysis was used to determine significant factors affecting survival. RESULTS: 100% survival follow up was achieved. Regular users of aspirin had >5% increased survival, which was significant, p=0.05, despite having a higher cardiovascular risk profile. Mode of death data was not available. CONCLUSIONS: Adjuvant aspirin post resection for potentially curative non-small cell lung cancer significantly increases survival. The mechanism of increased survival needs further investigation and is the basis for the trial: Adjuvant Aspirin for Non-Small cell Lung Cancer--The Big A Trial. www.TheBigATrial.co.uk.

Carotid artery diameter, plaque morphology, and hematocrit, in addition to percentage stenosis, predict reduced cerebral perfusion pressure during cardiopulmonary bypass: a mathematical model.

Cerebral complications after cardiac surgery are a significant cause of morbidity, mortality, and financial cost. Numerous risk factors have been proposed to explain the risk of cerebral damage. Carotid artery disease has an important role. Percentage carotid artery stenosis is the only measure of carotid artery disease that is used by cardiac surgeons to determine the need for either a carotid endarterectomy and/or a higher pump perfusion pressure. Identification of patients through their carotid plaque morphology who might benefit from higher pump perfusion pressures or concomitant carotid endarterectomy may reduce cerebral morbidity and mortality. A mathematical model using finite element analysis was created to model the carotid artery vessel and its stenotic plaque. Analysis showed that the degree of carotid artery stenosis, the length of the carotid artery plaque, the diameter of the carotid artery, and the blood hematocrit all independently significantly affect the required pump perfusion pressure to maintain adequate cerebral perfusion during cardiopulmonary bypass (CPB). The results from a mathematical model showed that carotid artery diameter, carotid artery plaque length, and hematocrit, in addition to percentage stenosis, should be included in any thought process involving carotid artery stenosis and cardiac surgery. Estimating cerebral risk during CPB should no longer rely on only the percentage stenosis.

Effect of foreign surface pacification with albumin, aprotinin, propofol, and high-density lipoprotein.

Foreign surface pacification may significantly reduce the detrimental effects of the cardiopulmonary bypass (CPB) circuit. To date, albumin is the only intervention consistently shown to be beneficial. The cationic physical properties of aprotinin and the known negative charge on the plastic CPB circuit mean that aprotinin binds to the CPB circuit and membrane oxygenator. A previously validated model involving a parallel plate glass slide technique was used. The effects of albumin, aprotinin, propofol, and high-density lipoprotein (HDL) were assessed by the ability to inhibit platelet adhesion to the glass slide surface. The experiment was repeated with collagen-coated glass slides to reproduce the clinical effect of endothelial denudation. The interventions were repeated on membrane oxygenators that are used for CPB. Aprotinin resulted in a minimal reduction in platelet adhesion to uncoated or collagen-coated glass slides. HDL significantly reduced platelet adhesiveness to uncoated or collagen-coated glass slides. Human albumin solution (HAS) and propofol produced an intermediary inhibitory effect on platelet adhesion on both collagen-coated and uncoated glass slides. The same effect was seen with membrane oxygenators that are used during CPB. HDL produced a significant reduction of neutrophil activation when used to coat a membrane oxygenator. Foreign surface pacification with HDL may have beneficial effects as assessed by platelet adhesiveness in a parallel plate assay. Aprotinin had minimal effect, and propofol had an intermediate effect. The same results were obtained using membrane oxygenators, confirming the validity of the parallel plate technique as clinically valid.

Aggressive zero balance ultrafiltration on CPB in patients with renal failure may cause cerebral edema: a theoretical analysis.

The objective of this study was to determine the brain volume changes that occur secondary to hemofiltration during cardiopulmonary bypass in patients with renal failure. We hypothesized that in patients with elevated urea levels, quick aggressive hemofiltration could be associated with cerebral edema. We constructed a simple two-compartment model similar to the urea kinetic model developed by Depner. Intracellular urea exit was assumed to be minimal based on known urea redistribution times. Calculations were based on a 70-kg patient, with an intracellular volume of 25 L, extracellular volume of 15 L, and a preoperative urea of 40 mmol/L filtered to a post-procedure urea of 6 mmol/L. Analysis showed that a standard size 1500-mL human brain filtered from a preoperative urea of 40 to 6 mmol/L over a short period will expand by 59 mL secondary to the osmotic disequilibrium secondary to hemofiltration (p < .05). The higher the preoperative urea, the larger the fluid shift. This figure does not include the cerebral edema component that is known to arise secondary to cardiopulmonary bypass. Significant cerebral edema theoretically occurs secondary to hemofiltration during cardiopulmonary bypass. More detailed mathematical urea kinetic analysis and clinical correlation are needed.

Hypertonic cardiopulmonary bypass primes and endothelial damage.

The objective of this study was to investigate whether hypertonic hyperosmolar primes solution (HHPS), with an osmolarity of 2300 mOsmol/L, causes endothelial damage/loss. The bodies' normal osmolarity is -280 mOsmol/L. Aortic endothelial cells were cultured and plated to confluence, confirmed by light microscopy, on a 96-well plate. Serial dilutions of HHPS (n = 10) were incubated with the cells (n = 160) for 1 hour. The plates were agitated to simulate flow that occurs during cardiopulmonary bypass (CPB). One half the cells (n = 80) were stained with crystal violet to provide a visual analogue of cell survival. The second half of the cells had the HHPS removed and replaced with culture medium and were incubated overnight before being stained with crystal violet. Optical densities were measured using an optical plate reader set at 470 nm. Analysis of the endothelium after 1 hour showed that HHPS (2300 mOsmol/L) and water (positive control for 100% cell death) resulted in equal cell death, which was significantly higher (p < .05) than any of the other osmolarities tested for. There was no significant difference in the endothelial death rates for osmolarities between 260 and 400 mOsmol/L. Results of overnight incubation showed that cells in contact with a solution of osmolarity >320 mOsmol/L resulted in a significantly greater endothelial cell death rate (p < .05). Our results indicate that the endothelium can be irreversibly damaged by HHPS with osmolarities >320 mOsmol/L. The experimental protocol showed that this endothelial damage, which obviously occurs at the time of contact with the HHPS, may only become manifest 24 hours later.

Colo-pleural fistula following pneumonectomy.

Following pneumonectomy and diaphragmatic reconstruction for carcinoid tumour, a fistula developed between the pneumonectomy space and the splenic flexure of the colon. The problem was successfully treated by colon resection and thoracoplasty.