Increased team familiarity for surgical time savings: Effective primarily in complex surgical cases

BACKGROUND

Cohesion between team members is critical for surgical performance. Our previous study has shown that the experience of working together (measured by Team Familiarity Score, TFS) helps reduce procedure time (PT). However, that conclusion was found in a relatively small sample size. With a large dataset including mixed general surgical procedures, we hypothesize that team familiarity makes a significant contribution to the improvement of team performance in complex cases, rather than in medium or basic surgical cases, measured by the procedure time, length of hospital stays (LOS), and surgical cost (COST).

STUDY DESIGN

Patient demographics, operation, and patient outcome data of 922 general surgery cases were included. The cases were divided into three subgroups, including basic, medium, and complex surgical procedures. TFS and an Index of Difficulty of Surgery (IDS) were calculated for each procedure. Simple linear regression and random forest regressions were performed to analyze the association between surgical outcomes and all included independent variables (TFS, IDS, patient age, patient weight, and team size).

RESULTS

When applied to complex cases, procedure time (r = -0.21) and cost (r = -0.23) dropped as TFS increases. In basic and medium surgical cases, increasing team familiarity failed to shorten the procedure time on average.

CONCLUSION

Team familiarity is more important in complex cases because there is greater potential for improvement through team collaboration compared to basic and medium cases. Caution will be needed when applying team familiarity scores for examining surgical team performance in large databases with skewed to basic surgical cases.

Race and sex diversity in Canadian academic surgical societies

BACKGROUND

It is vital for national professional surgical societies to embrace diversity, inclusion, and equity. This study examines race and sex diversity in two Canadian surgical societies.

METHODS

Websites of the Canadian Society of Cardiac Surgeons (CSCS) and the Canadian Association of General Surgeons (CAGS) and previous programs of their annual meetings were reviewed. Leadership positions, conference speakers, and award winners were categorized by race and sex.

RESULTS

White males made up the largest category of Cardiac Surgery meeting speakers (73/142 [51%]), CAGS committee members (89/198 [45%]), CAGS past presidents (38/43 [88%]), and General Surgery meeting speakers (841/1472 [57%]). Of the 17 members that made up the CSCS board of directors and officers, 8 were White males (47%), 5 were BIPOC males (29%), 3 were White females (18%), and 1 was a BIPOC female (6%). Of the 42 members of the CAGS board of directors and advisory committee, 16 were White males (38%), 5 were BIPOC males (12%), 17 were White females (40%), and 4 were BIPOC females (10%).

CONCLUSIONS

BIPOC individuals and females are underrepresented in both societies compared to White males. However, in CAGS, improvements in representation can be seen in recent years. It is important that both of these organizations continue to embrace diversity.

Conflict of interest disclosure by US cardiothoracic surgeons

BACKGROUND

Surgeon-industry collaboration is a key driver of advancement in surgical technology and practice. Disclosures of financial relationships between investigators and industries are important to ensure transparent and critical evaluation of literature.

METHODS

All American cardiothoracic (CT) surgeons who published in three major CT surgery journals in 2019 were identified. Whether these surgeons disclosed any conflicts of interest was recorded and compared to actual payments received within 5 years of publication as reported by the Centers for Medicare and Medicaid Services data.

RESULTS

In the study period, there were 1079 unique manuscripts involving 885 American CT surgeons as authors, which combined for 2719 author instances. Of these, 96.2% of authors (851 of 885) received payments from companies. The authors who received payments produced 2651 author instances (97.4%). Financial disclosure was reported in only 11.4% (301 of 2651) of these instances. In total, 851 surgeons received more than $187 million over 5 years, with the highest-paid surgeon receiving an average of over $5.9 million per year. The largest individual payments were from "Associated Research Funding," with over $115 million being paid to 277 surgeons over 5 years. The top paying company issued over $96.5 million to American CT surgeons over 5 years.

CONCLUSIONS

Nearly all the reviewed publications in three top CT surgery journals were by surgeons who received payments from companies, but very few of these payments were recorded as potential conflicts of interest. A more consistent and robust policy of COI disclosure is needed to reduce perceptions of bias.

Validity Evidence for Procedure-specific Competence Assessment Tools in Orthopaedic Surgery: A Scoping Review

INTRODUCTION

Competency-based training requires frequent assessment of residents' skills to determine clinical competence. This study reviews existing literature on procedure-specific competence assessment tools in orthopaedic surgery.

METHODS

A systematic search of eight databases up to May 2023 was conducted. Two reviewers independently assessed validity evidence and educational utility of each assessment tool and evaluated studies' methodological quality.

RESULTS

Database searching identified 2,556 unique studies for title and abstract screening. Full texts of 290 studies were reviewed; 17 studies met the inclusion criteria. Bibliography review identified another five studies, totaling 22 studies examining 24 assessment tools included in the analysis. These tools assessed various orthopaedic surgery procedures within trauma, sports medicine, spine, and upper extremity. Overall validity evidence was low across all studies, and was lowest for consequences and highest for content. Methodological quality of studies was moderate. Educational utility assessment was not explicitly done for most tools.

DISCUSSION

The paucity of current procedure-specific assessment tools in orthopaedic surgery lacks the validity evidence required to be used reliably in high-stake summative assessments. Study strengths include robust methodology and use of an evidence-based validity evidence framework. Poor-quality existing evidence is a limitation and highlights the need for evidence-based tools across more subspecialties.

Preoperative Mediastinal Staging in Early-Stage Lung Cancer: Targeted Nodal Sampling is Not Inferior to Systematic Nodal Sampling

OBJECTIVE

To determine whether Targeted Sampling (TS), which omits biopsy of Triple Normal lymph nodes (LNs) on PET, CT and EBUS is non-inferior to Systematic Sampling (SS) of mediastinal LNs during EBUS for staging of patients with early-stage NSCLC.

METHODS

cN0-N1 patients with suspected NSCLC eligible for EBUS based on PET/CT were enrolled in this prospective, multi-centre trial. During EBUS, all patients underwent TS, and then crossed over to SS, whereby at least 3 mediastinal LN stations (4R, 4L, 7) were routinely sampled. Gold standard of comparison was pathological results. Based on the previous feasibility trial, a non-inferiority margin of 6% was established for difference in missed nodal metastasis (MNM) incidence between TS and SS. McNemar's test on paired proportions was used to determine MNM incidence for each sampling method. Analysis was per-protocol using a level of significance of p<0.05.

RESULTS

Between November 2020 and April 2022, 91 patients were enrolled at 6 high-volume Canadian tertiary care centres. A total of 256 LNs underwent TS and SS. Incidence of MNM was 0.78% in SS and 2.34% in TS, with an absolute difference of 1.56% (95% CI: -0.003% to 4.1%; p=0.13). This falls within the non-inferiority margin. A total of 6/256 LNs from 4 patients that were not sampled by TS were found to be malignant when sampled by SS.

CONCLUSION

In high volume thoracic endosonography centres, TS is not inferior to SS in nodal staging of early-stage NSCLC. This results in change of clinical management for a minority of patients.

Changes in Sarcopenia Status Predict Survival Among Patients with Resectable Esophageal Cancer

BACKGROUND

Sarcopenia is a predictor of survival in patients with esophageal cancer. The objective of this research was to obtain insight into how changes in sarcopenia influence survival in resectable esophageal cancer.

PATIENTS AND METHODS

A retrospective cohort of patients with esophageal cancer undergoing tri-modality therapy was selected. Body composition parameters from the staging, post-neoadjuvant, and 1-year surveillance computed tomography (CT) scans were calculated. Overall survival (OS) and disease-free survival (DFS) were evaluated using the Kaplan-Meier method and log-rank test, as well as multivariable Cox-proportional hazards models.

RESULTS

Of 141 patients, 118 had images at all three timepoints. The median DFS and OS were 33.2 [95% confidence interval (CI) 19.1-73.7] and 34.5 (95% CI 23.1-57.6) months, respectively. Sarcopenia classified by the staging CT was present in 20 (17.0%) patients. This changed to 45 (38.1%) patients by the post-neoadjuvant scan, and 44 (37.3%) by the surveillance scan. In multivariable analysis, sarcopenia at the post-neoadjuvant scan was significantly associated with OS [hazards ratio (HR) 2.65, 95% CI 1.59-4.40; p < 0.001] and DFS (HR 1.80, 95% CI 1.03-3.13; p = 0.038). The net change in skeletal muscle index was associated with OS (HR 0.93, 95% CI 0.90-0.97; p < 0.001) and DFS (HR 0.94, 95% CI 0.91-0.98; p = 0.001).

CONCLUSIONS

Patients who develop sarcopenia as a consequence of skeletal muscle wasting during neoadjuvant therapy are at risk for worse DFS and OS. Patients who have a net loss of muscle over time may be at high risk for early disease recurrence.

Assessment of a Novel, Adjustable Task Trainer for Cardiac Surgical Skills

INTRODUCTION

A recent needs assessment in Canadian cardiac surgery programs identified the desire for a coronary artery bypass (CABG) and aortic valve replacement (AVR) simulation model for home practice. We aimed to develop and assess a portable, adjustable task trainer for cardiac surgical skills with high functional task alignment.

METHODS

Intraoperative measurements were taken from patients undergoing elective CABG and AVR (N = 30). Measurements were taken in 3 axes and used to create a chest cavity that resembles the mediastinal constraints of a patient undergoing CABG and AVR. The task trainer is adjustable on the following 3 levels: (1) size of the incision, (2) depth of the chest, and (3) relative position of coronary artery or aortic valve model within the chest. Three groups (novices, intermediates, and experts) of cardiac surgery members evaluated the task trainer for functional task alignment and construct validity.

RESULTS

The CABG and AVR model had high functional task alignment. There was a high satisfaction for both models and all participants would recommend the AVR and CABG model as an educational tool. Performance time significantly differed between the groups for both models (CABG: P = 0.032 and AVR: P = 0.001), as well as number of errors (CABG: P = 0.04 and AVR: P = 0.043).

CONCLUSIONS

Using real patient data, we were able to develop an adjustable task trainer for training principles of CABG and AVR. Our pilot study provides preliminary sources of evidence for validity and future study will look to assess transferability of skill to the operating room.

Sex and racial diversity in Canadian academic surgery

To ensure equitable representation of women and BIPOC (Black, Indigenous, person of colour) individuals in surgical specialties, it is first necessary to understand the presence and extent of the disparities that exist. We explored the websites of the 17 Canadian faculties of medicine to examine sex and racial diversity in surgical specialties and in surgical leadership positions in Canada. We categorized faculty members of each department of surgery as either male or female and White or BIPOC. The relative percentage of female academic surgeons was very low compared with Canadian demographic data, and the relative percentage of BIPOC academic surgeons was similar to Canadian demographic data. Our observations suggest that actions must be taken to improve diversity and inclusion in surgery.

Oral care reduces incidence of pneumonia after esophagectomy: systematic review and meta-analysis

PURPOSE

Post-operative pneumonia after esophagectomy is a major contributor to morbidity and mortality. Prior studies have demonstrated a link between the presence of pathologic oral flora and the development of aspiration pneumonia. The objective of this systematic review and meta-analysis was to evaluate the effect of pre-operative oral care on the incidence of post-operative pneumonia after esophagectomy.

METHODS

A systematic search of the literature was performed on September 2, 2022. Screening of titles and abstracts, full-text articles, and evaluation of methodological quality was performed by two authors. Case reports, conference proceedings, and animal studies were excluded. A meta-analysis of peri-operative oral care on the odds of post-operative pneumonia after esophagectomy was performed using Revman 5.4.1 with a Mantel-Haenszel, random-effects model.

RESULTS

A total of 736 records underwent title and abstract screening, leading to 28 full-text studies evaluated for eligibility. A total of nine studies met the inclusion criteria and underwent meta-analysis. Meta-analysis revealed a significant reduction in post-operative pneumonia among patients undergoing pre-operative oral care intervention compared to those without an oral care intervention (OR 0.57, 95% CI 0.43-0.74, p < 0.0001; I² = 49%).

CONCLUSION

Pre-operative oral care interventions have significant potential in the reduction of post-operative pneumonia after esophagectomy. North American prospective studies, as well as studies on the cost-benefit analysis, are required.

Sarcopenia in Lung Cancer: A Narrative Review

It has been over 10 years since the relationship between sarcopenia and lung cancer was first explored. Since then, sarcopenia research has progressed substantially, and the prognostic value of this condition is becoming increasingly apparent. Prior systematic reviews and meta-analyses have established sarcopenia to be negatively associated with disease-free and overall-survival, as well as a major risk factor for post-operative complications. The bulk of the literature has explored sarcopenia in the resectable setting, with less emphasis placed on studies evaluating this condition in advanced disease. In this up-to-date review, an examination of the literature exploring the association between sarcopenia and long-term outcomes in advanced lung cancer is provided. We further explore the association between adverse events of medical therapy and the role of sarcopenia as a predictor of tumor response. Finally, the interventions on sarcopenia and cancer cachexia are reviewed, with an emphasis placed on prospective studies.

Learning objectives for thoracic surgery: developing a national standard for undergraduate medical education

BACKGROUND

The Continuing Professional Development (CPD) (Education) Committee of the Canadian Association of Thoracic Surgeons (CATS) has established a goal of describing the essential knowledge of thoracic surgery. We aimed to develop a national standardized set of undergraduate learning objectives for thoracic surgery.

METHODS

We obtained these learning objectives from 4 medical schools in Canada. These 4 institutions were selected to provide a broad geographical representation of medical schools of varying sizes and of both official languages. The resulting list of learning objectives underwent critical review by the CPD (Education) Committee, made up of 5 Canadian community and academic thoracic surgeons, 1 thoracic surgery fellow and 2 general surgery residents. A national survey was developed and circulated to all CATS members (n = 209). Respondents were asked to indicate on a 5-point Likert scale whether each objective should be a priority for all medical students.

RESULTS

Among 209 CATS members, 56 responded (response rate 27%). The mean length of experience in clinical practice among survey respondents was 10.6 (standard deviation 10.0) years. Respondents most commonly reported teaching or supervising medical students monthly (37.0%), followed by daily (29.6%). Eight of the 10 proposed objectives received a mean Likert score of 4/5 or higher and were selected for inclusion in the final list. A finalized list of 8 learning objectives was created, following a final review from the CATS Executive Committee.

CONCLUSION

We developed a standardized set of learning objectives for medical students that was reflective of the core concepts within thoracic surgery.

Factors Associated With Resident Research Success: An Analysis of Canadian General Surgery Trainees

OBJECTIVE

Better understanding the research productivity of Canadian general surgery residents and factors associated with success would provide a valuable reference and help inform actions to enable success. We aimed to characterize the research productivity of Canadian general surgery residents and to evaluate factors associated with residents' research quantity and impact.

DESIGN

A cross-sectional, observational study was performed using publicly available data evaluating Canadian General Surgery resident research productivity. Research productivity was characterized using measures including publications per postgraduate year (PGY) and CiteScore among others. Residency programs were then comparatively assessed using a multivariable logistic regression to evaluate program and resident factors associated with achieving >50th percentile research productivity.

SETTING AND PARTICIPANTS

All General Surgery residents from English speaking Canadian training programs were included in this study, which was completed at the University of Alberta, a tertiary level academic center in Edmonton, Canada.

RESULTS

A wide range of resident research productivity was observed across Canada with the median publications per PGY of 0.29, and the median sum of a resident's publication CiteScores of 2.05. The median h-index was 0.90. Graduate degree completion and publication experience prior to residency were significantly associated with higher publications per PGY (OR 2.94 and OR 2.10, respectively), as well as higher mean CiteScore (OR 3.42 and 2.24). The program factors that were assessed, including program size, research blocks, mandatory projects, or higher staff research productivity, did not show significant association with increased research output.

CONCLUSIONS

There is a wide range in research output by general surgery residents across the country. Successful completion of graduate degrees and the experience of publication prior to residency are associated with higher research productivity and impact.

ERAS guidelines for esophagectomy: adherence patterns among Canadian thoracic surgeons

Enhanced recovery after surgery (ERAS) guidelines have been incorporated across surgical specialties supported by the publication of evidence-based guidelines. The purpose of this research was to explore adherence to such guidelines among Canadian thoracic surgeons with respect to esophagectomy. A standardized questionnaire was developed comprising 43 validated ERAS recommendations. Additional questions such as the number of annual esophagectomies per institution, the clinical practice environment of the survey responder, preferred operative approach, and responder demographics were included. The survey was circulated to all Canadian Association of Thoracic Surgery (CATS) members and remained open for a four month period. Of the 136 CATS members, 74 (54.4%) completed the survey. Among responders, 29 (40.3%) did have a standard ERAS protocol at their institution. The majority of the responders practiced at an academic center (50, 88.3%). A self-reported adherence rate greater than 80% was observed in six out of 12 of the pre-operative ERAS recommendations, two out of eight of the intraoperative, and seven out of 23 of the post-operative ERAS recommendations. Among the five recommendations associated with high levels of evidence, two had been incorporated into practice by the majority of responders. Out of the 29 strong recommendations, 24 were incorporated into practice by the majority of responders. Canadian thoracic surgeons' express practices that are largely consistent with strongly recommended ERAS guidelines in patients undergoing esophagectomy. ERAS guidelines continue to be instrumental in the improvement of perioperative care; however, high adherence is ultimately necessary for optimal patient outcomes.

Cellulose: A Review of Water Interactions, Applications in Composites, and Water Treatment

Cellulose is known to interact well with water, but is insoluble in it. Many polysaccharides such as cellulose are known to have significant hydrogen bond networks joining the molecular chains, and yet they are recalcitrant to aqueous solvents. This review charts the interaction of cellulose with water but with emphasis on the formation of both natural and synthetic fiber composites. Covering studies concerning the interaction of water with wood, the biosynthesis of cellulose in the cell wall, to its dispersion in aqueous suspensions and ultimately in water filtration and fiber-based composite materials this review explores water-cellulose interactions and how they can be exploited for synthetic and natural composites. The suggestion that cellulose is amphiphilic is critically reviewed, with relevance to its processing. Building on this, progress made in using various charged and modified forms of nanocellulose to stabilize oil-water emulsions is addressed. The role of water in the aqueous formation of chiral nematic liquid crystals, and subsequently when dried into composite films is covered. The review will also address the use of cellulose as an aid to water filtration as one area where interactions can be used effectively to prosper human life.

Presurgical radiation and chemotherapy in preparation for thoracic tumor resection

PURPOSE OF REVIEW

This article aims at describing the role of neoadjuvant chemotherapy, radiation therapy as well the novel immunotherapy and targeted therapy in thoracic oncology with focus on anesthetic considerations of such treatments for the surgical patient.

RECENT FINDINGS

In recent years, immune check point inhibitors have changed the landscape of thoracic oncology treatment. In this review, we summarize the key studies that have been fundamental in this change.

SUMMARY

Rather than a comprehensive review, the purpose of this work is to provide the reader with an overview of the most common neoadjuvant regimens used in current practice, with the corresponding most prevalent adverse effects as it pertains for patients with esophageal and lung cancer, malignant pleural mesothelioma and mediastinal tumors. Considerations relevant to the anesthesiologist, including specific toxicities related to each treatment type, and the impact of each treatment type on perioperative outcomes and complications will be discussed.

Sarcopenia reduces overall survival in unresectable oesophageal cancer: a systematic review and meta-analysis

Sarcopenia measured through body composition analysis is emerging as an important prognosticator among various malignancies, including oesophageal cancer. Skeletal muscle index (SMI) as determined by the third lumbar vertebrae on cross-sectional CT images has been demonstrated as a predictor of overall survival in oesophageal cancer, using pre-defined cut off values for sarcopenia. However, this is largely within the setting of resectable disease. The primary objective of this systematic review and meta-analysis was to determine the effect of sarcopenia defined by SMI on overall-survival in patients with unresectable oesophageal cancer. On 30 January 2021, a systematic search of the literature was conducted to identify the role of SMI among patients with unresectable oesophageal cancer, with overall survival as the primary outcome. Databases included MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library. Inclusion criteria included age >18, diagnosis of oesophageal cancer, and non-operative management. A meta-analysis was conducted using RevMan 5.4.1 using an inverse variance, random effects model. After the removal of duplicates, 2755 unique search results were obtained. Manual screening of titles and abstracts resulted in 287 full text articles that were reviewed. Of these, five studies met the inclusion criteria with data evaluating the effect of sarcopenia defined by SMI on overall survival. A total of 783 patients, the majority of which were male (n = 638, 81%), with a mean age of 68 ± 2.3 years were included. 641 (82%) patients were diagnosed with squamous cell carcinoma. Sarcopenia, as determined by SMI using pre-defined cut-off values, was reported in 517 patients (66%). Meta-analysis demonstrated decreased overall survival in the sarcopenia group compared with the non-sarcopenia group (HR = 1.51; 95% CI 1.21-1.89; P = 0.0003; I²  = 0%; Figure 1). No significant publication bias was noted on assessment of funnel plot and Egger's test (P = 0.295). Sarcopenia as defined by SMI is predictive of overall survival among patients with nonoperative oesophageal cancer. Further analysis on the effect of sarcopenia on treatment related adverse effects and complications, particularly related to chemotherapy, radiotherapy, and oesophageal stenting, is needed to identify the degree of prognostication offered by body composition analysis. Studies on the modifiability of sarcopenia will help determine the utility of nutritional interventions.

Routine systematic sampling versus targeted sampling during endobronchial ultrasound: A randomized feasibility trial

OBJECTIVE

Triple normal lymph nodes, appearing benign on computed tomography, positron emission tomography, and endobronchial ultrasound, have less than a 6% probability of malignancy. We hypothesized that targeted sampling (TS), which omits biopsy of triple normal lymph nodes during endobronchial ultrasound, is not an inferior staging strategy to systematic sampling (SS) of all lymph nodes.

METHODS

A prospective randomized feasibility trial was conducted to decide on the progression to a pan-Canadian trial comparing TS with SS. Patients with cN0-N1 non-small cell lung cancer undergoing endobronchial ultrasound were randomized to TS or SS. Lymph nodes in the TS arm crossed over to receive SS. Progression criteria included recruitment rate (70% minimum), procedure length (no significant increase for TS), and incidence of missed nodal metastasis (<6%). Mann-Whitney U test and McNemar's test on paired proportions were used for statistical comparisons.

RESULTS

The progression criterion of 70% recruitment rate was achieved early, triggering a planned early stoppage of the trial. Nineteen patients were allocated to each arm. The median procedure length for TS was significantly shorter than SS (3.07 vs 19.07 minutes; P < .001). After crossover analysis, 5.45% (95% confidence interval, 1.87-14.85) of lymph nodes in the TS arm were upstaged from N0 to N2, but this incidence of missed nodal metastasis was below the 6% threshold. During surgical resection, the nodal upstaging incidence from N0 to N2 was 0% for 15 lymph nodes in each arm.

CONCLUSIONS

Progression criteria to a pan-Canadian, noninferiority crossover trial comparing TS with SS have been met, and such a trial is warranted.

Validity Evidence for Procedure-Specific Competency Assessment Tools in Cardiovascular and Thoracic Surgery: A Scoping Review

OBJECTIVE

Surgical education has shifted from a time-based approach to the achievement and demonstration of procedural competency. High quality, objective assessment instruments are required to support this new approach. This study comprehensively reviewed the literature to identify and evaluate available procedure-specific assessment instruments in cardiothoracic and vascular surgery.

DESIGN

A systematic search of 8 databases identified studies containing procedure-specific operative assessment instruments in cardiothoracic and vascular surgery. Generic global rating scales were excluded, unless modified to be procedure-specific. Two reviewers independently evaluated the validity evidence, methodological rigour and educational utility of each instrument using objective scoring criteria. Validity evidence was evaluated with a scoring tool aligned with the contemporary framework of validity. Methodological rigour was evaluated using the Medical Education Research Study Quality Instrument. Educational utility was evaluated according to the Accreditation Council for Graduate Medical Education (ACGME) framework.

RESULTS

There were 2130 unique studies describing procedure-specific assessment in surgery. Of these, 9 studies evaluating 8 procedure-specific assessment instruments met inclusion criteria for cardiothoracic and vascular surgery. Four instruments were identified in thoracic surgery, 2 in cardiac surgery, and 2 in vascular surgery. Only 1 instrument was designed to evaluate surgeon performance, with the remainder designed to evaluate residents. No single instrument scored the maximum score of 15 for validity evidence. The highest score was 11, with 62.5% (n = 5) of instruments scoring greater than 10. All tools attained high scores in content validity, with minimal evidence generally presented regarding the consequences of assessment using a particular instrument. All but 1 instrument scored greater than 11 out of a maximum 16.5 points for methodological rigour. Very few studies reported on the ACGME domains of educational utility.

CONCLUSIONS

In an era where surgical education is shifting towards the demonstration of procedural competency, objective procedure-specific assessment is critical. This review identified that few procedure-specific assessment instruments in cardiothoracic and vascular surgery exist, emphasizing the need for such instruments to ensure the success of competency-based education models.

Stigma in Early-Stage Lung Cancer

BACKGROUND

The phenomenon of lung cancer stigma has been firmly established in the literature. However, studies have predominantly focused on patients with advanced disease, whose experiences may differ from patients with earlier stage, surgically resectable lung cancer and an improved prognosis.

PURPOSE

The objective of the study was to examine the stigma experienced in a Canadian population with early-stage, resectable lung cancer.

METHODS

Patients with newly diagnosed lung cancer were enrolled at a tertiary thoracic surgery clinic. The 25-item Lung Cancer Stigma Inventory (LCSI) was self-administered by patients to quantitatively measure experiences of lung cancer stigma. LCSI results informed the development of a semi-structured focus group and individual interviews.

RESULTS

Of the 53 participants completing the survey, 38 (72%) met established LCSI score threshold, indicating a clinically meaningful level of stigma. No significant relationship was found between total LCSI scores and any demographic variable. Analysis of qualitative data revealed multiple themes related to experiences of lung cancer stigma. The major themes were classified into four categories: impact of the association between lung cancer and smoking, societal attitudes and assumptions, personal choices in relation to diagnosis, and experiences related to care.

CONCLUSIONS

A surgical population of patients with predominantly early-stage lung cancer experienced lung cancer stigma at a high incidence and a level similar to previously studied populations with more advanced disease. The qualitative results support the quantitative findings that respondents experienced more internal stigma than either perceived stigma from others or constrained disclosure related to their diagnosis.

Flexible and digestible wood caused by viral-induced alteration of cell wall composition

Woody plant material represents a vast renewable resource that has the potential to produce biofuels and other bio-based products with favorable net CO₂ emissions.^1,2 Its potential has been demonstrated in a recent study that generated novel structural materials from flexible moldable wood.³ Apple rubbery wood (ARW) disease is the result of a viral infection that causes woody stems to exhibit increased flexibility.⁴ Although ARW disease is associated with the presence of an RNA virus⁵ known as apple rubbery wood virus (ARWV), how the unique symptoms develop is unknown. We demonstrate that the symptoms of ARWV infections arise from reduced lignification within the secondary cell wall of xylem fibers and result in increased wood digestibility. In contrast, the mid-lamellae region and xylem ray cells are largely unaffected by the infection. Gene expression and proteomic data from symptomatic xylem clearly show the downregulation of phenylalanine ammonia lyase (PAL), the enzyme catalyzing the first committed step in the phenylpropanoid pathway leading to lignin biosynthesis. A large increase in soluble phenolics in symptomatic xylem, including the lignin precursor phenylalanine, is also consistent with PAL downregulation. ARWV infection results in the accumulation of many host-derived virus-activated small interfering RNAs (vasiRNAs). PAL-derived vasiRNAs are among the most abundant vasiRNAs in symptomatic xylem and are likely the cause of reduced PAL activity. Apparently, the mechanism used by the virus to alter lignin exhibits similarities to the RNAi strategy used to alter lignin in genetically modified trees to generate comparable improvements in wood properties.6, 7, 8

Video abstract

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Apple rubbery wood (ARW) symptoms are caused by decreased lignin in woody tissue

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RNA-seq, proteomics, and metabolomics suggest phenylalanine levels decrease

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Virus-activated small interfering RNAs (vasiRNAs) are generated in response to ARWV infection

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VasiRNAs cause siRNA-based downregulation of phenylalanine ammonia

An atlas of Arabidopsis protein S-acylation reveals its widespread role in plant cell organization and function

S-acylation is the addition of a fatty acid to a cysteine residue of a protein. While this modification may profoundly alter protein behaviour, its effects on the function of plant proteins remains poorly characterized, largely as a result of the lack of basic information regarding which proteins are S-acylated and where in the proteins the modification occurs. To address this gap in our knowledge, we used an optimized acyl-resin-assisted capture assay to perform a comprehensive analysis of plant protein S-acylation from six separate tissues. In our high- and medium-confidence groups, we identified 1,849 cysteines modified by S-acylation, which were located in 1,640 unique peptides from 1,094 different proteins. This represents around 6% of the detectable Arabidopsis proteome and suggests an important role for S-acylation in many essential cellular functions including trafficking, signalling and metabolism. To illustrate the potential of this dataset, we focus on cellulose synthesis and confirm the S-acylation of a number of proteins known to be involved in cellulose synthesis and trafficking of the cellulose synthase complex. In the secondary cell walls, cellulose synthesis requires three different catalytic subunits (CESA4, CESA7 and CESA8) that all exhibit striking sequence similarity and are all predicted to possess a RING-type zinc finger at their amino terminus composed of eight cysteines. For CESA8, we find evidence for S-acylation of these cysteines that is incompatible with any role in coordinating metal ions. We show that while CESA7 may possess a RING-type domain, the same region of CESA8 appears to have evolved a very different structure. Together, the data suggest that this study represents an atlas of S-acylation in Arabidopsis that will facilitate the broader study of this elusive post-translational modification in plants as well as demonstrating the importance of further work in this area.

An atlas of Arabidopsis protein S-acylation reveals its widespread role in plant cell organization and function

S-acylation is the addition of a fatty acid to a cysteine residue of a protein. While this modification may profoundly alter protein behaviour, its effects on the function of plant proteins remains poorly characterized, largely as a result of the lack of basic information regarding which proteins are S-acylated and where in the proteins the modification occurs. To address this gap in our knowledge, we used an optimized acyl-resin-assisted capture assay to perform a comprehensive analysis of plant protein S-acylation from six separate tissues. In our high- and medium-confidence groups, we identified 1,849 cysteines modified by S-acylation, which were located in 1,640 unique peptides from 1,094 different proteins. This represents around 6% of the detectable Arabidopsis proteome and suggests an important role for S-acylation in many essential cellular functions including trafficking, signalling and metabolism. To illustrate the potential of this dataset, we focus on cellulose synthesis and confirm the S-acylation of a number of proteins known to be involved in cellulose synthesis and trafficking of the cellulose synthase complex. In the secondary cell walls, cellulose synthesis requires three different catalytic subunits (CESA4, CESA7 and CESA8) that all exhibit striking sequence similarity and are all predicted to possess a RING-type zinc finger at their amino terminus composed of eight cysteines. For CESA8, we find evidence for S-acylation of these cysteines that is incompatible with any role in coordinating metal ions. We show that while CESA7 may possess a RING-type domain, the same region of CESA8 appears to have evolved a very different structure. Together, the data suggest that this study represents an atlas of S-acylation in Arabidopsis that will facilitate the broader study of this elusive post-translational modification in plants as well as demonstrating the importance of further work in this area.

Validity Evidence for Procedure-specific Competence Assessment Tools in General Surgery: A Scoping Review

OBJECTIVE

This study aims to provide a focused and detailed assessment of the validity evidence supporting procedure-specific operative assessment tools in general surgery.

SUMMARY OF BACKGROUND DATA

Competency-based assessment tools should be supported by robust validity evidence to be used reliably for evaluation of operative skills. The contemporary framework of validity relies on five sources of evidence: content, response process, internal structure, relation to other variables, and consequences.

METHODS

A systematic search of 8 databases was conducted for studies containing procedure-specific operative assessment tools in general surgery. The validity evidence supporting each tool was assessed and scored in alignment with the contemporary framework of validity. Methodological rigour of studies was assessed with the Medical Education Research Study Quality Instrument. The educational utility of each tool was assessed with the Accreditation Council for Graduate Medical Education framework.

RESULTS

There were 28 studies meeting inclusion criteria and 23 unique tools were assessed. Scores for validity evidence varied widely between tools, ranging from 3 - 14 (maximum 15). Medical Education Research Study Quality Instrument scores assessing the quality of study methodology were also variable (8.5-15.5, maximum 16.5). Direct reporting of educational utility criteria was limited.

CONCLUSIONS

This study has identified a small group of procedure-specific operative assessment tools in general surgery. Many of these tools have limited validity evidence and have not been studied sufficiently to be used reliably in high-stakes summative assessments. As general surgery transitions to competency-based training, a more robust library of operative assessment tools will be required to support resident education and evaluation.

Yield of routine staging laparoscopy in patients with gastric cancer in Alberta, Canada

Background:

Despite guidelines recommending diagnostic laparoscopy in patients with gastric cancer, implementation is low. We aimed to explore trends in the use of laparoscopy for staging of gastric cancer in Alberta, Canada, determine the rate of positive findings and identify factors predictive of positive staging laparoscopy (SL) findings in this patient population.

Methods:

In August 2018, we sent a survey to all general surgeons in Alberta who were members of the Alberta Association of General Surgeons to identify those treating gastric cancer. The survey inquired about type of practice (academic or community), gastric cancer case volume, routine versus selective use of SL and, if selective use of SL, criteria used to select cases. Participants were also asked to provide data from their SL cases from July 2007 to February 2019. We double-checked surgeon records with chart review. The primary outcome was evidence of metastatic disease on SL or cytologic examination or both. We performed logistic regression analysis to identify factors predictive of positive laparoscopy findings.

Results:

The survey was completed by 41 of 127 surgeons (response rate 32.3%). We reviewed 116 cases from 5 surgeons at 4 centres. Gross metastatic disease or positive findings on cytologic examination or both were identified in 37 patients (31.9%). On univariate analysis, the following were associated with an increased risk of identification of metastatic disease at laparoscopy: visualization of the primary tumour on computed tomography (CT) (odds ratio [OR] 9.8, 95% confidence interval [CI] 1.2–76.5), presence of abdominal lymphadenopathy greater than 1 cm (OR 2.4, 95% CI 1.1–5.4) and presence of ascites (OR 19.1, 95% CI 2.2–161.8). Visualization of the primary tumour on CT (OR 8.4, 95% CI 1.0–68.3) and the presence of ascites (OR 15.9, 95% CI 1.8–137.0) remained statistically significant predictors on multivariate analysis.

Conclusion:

Metastatic disease was identified at SL in almost one-third of cases, which suggests that SL should still be used routinely in gastric cancer staging in Canadian centres. Our study identified several preoperative imaging findings associated with evidence of metastatic disease on laparoscopy; however, further studies are needed to establish robust predictors of positive findings before advocating for a selective SL approach.

Clinical Validation of the Canada Lymph Node Score for Endobronchial Ultrasound

BACKGROUND

The Canada Lymph Node Score (CLNS) uses four sonographic criteria to predict the risk of malignancy in lymph nodes during endobronchial ultrasound (EBUS). CLNS may play a role in identifying targets for biopsy or re-biopsy during invasive mediastinal staging for lung cancer. However, CLNS has not yet been prospectively validated in routine clinical practice.

METHODS

CLNS scores for each lymph node biopsied during EBUS were prospectively captured for one year (2019). CLNS and the presence of malignancy in each node were compared. Univariate binary logistic regression was completed for each ultrasonographic feature, as well as a multivariate logistic regression model.

RESULTS

CLNS and diagnostic pathology results were available for 367 lymph nodes. Incidence of malignancy increased with higher scores. Scores ≥3 were significantly associated with malignancy (specificity 84.4%, positive likelihood ratio 4.0). Area under the curve was 0.76, indicating a good ability of the model to predict presence or absence of malignancy. Nodes scoring <2 and negative on CT and PET were malignant in 10.1%.

CONCLUSIONS

CLNS correlates with the presence or absence of malignancy in thoracic lymph nodes, and may serve as an adjunct to currently available methods of invasive and non-invasive mediastinal staging. CLNS may be most helpful to select which non-diagnostic nodes require re-biopsy. There is a significant risk of a false negative result even with a score of 0, and using a combination of low CLNS and negative conventional radiology to obviate the need for any initial biopsy remains to be studied in prospective trials.

Learner Phenotypes in Competency-Based Medical Education

With the launch of competency-based medical education internationally, the practical realities of implementation have failed to live up to many of the proposed theoretical benefits. Specifically, as educators we have observed a number of assessment challenges that seem directly related to identified learner phenotypes. This commentary seeks to describe these specific learner phenotypes, along with actionable recommendations for programs and their competence committees in order to overcome the associated obstacles in assessment. We describe strategies related to both the individual and program level, which can be utilized for both short-term adjustments and long-term programmatic transformation.

Gastric ischemic conditioning prior to esophagectomy reduces anastomotic leaks and strictures: a systematic review and meta-analysis

BACKGROUND

Gastric ischemic conditioning (GIC) is a strategy to promote neovascularization of the gastric conduit to reduce the risk of anastomotic complications following esophagectomy. Despite a number of studies and reviews published on the concept of ischemic conditioning, there remains no clear consensus regarding its utility. We performed an updated systematic review and meta-analysis to determine the impact of GIC, particularly on anastomotic leaks, conduit ischemia, and strictures.

METHODS

A systematic search of MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library was performed on February 5th, 2020 by a university librarian after selection of key search terms with the research team. Inclusion criteria included human participants undergoing esophagectomy with gastric conduit reconstruction, age ≥ 18, N ≥ 5, and GIC performed prior to esophagectomy. Our primary outcome of interest was anastomotic leaks. Our secondary outcome was gastric conduit ischemia, anastomotic strictures, and overall survival. Meta-analysis was performed with RevMan 5.4.1 using a Mantel-Haenszel fixed-effects model.

RESULTS

A total of 1712 preliminary studies were identified and 23 studies included for final review. GIC was performed in 1178 (53.5%) patients. Meta-analysis revealed reduced odds of anastomotic leaks (OR 0.67; 95% CI 0.46-0.97; I² = 5%; p = 0.03) and anastomotic strictures (OR 0.48; 95% CI 0.29-0.80; I² = 65%; p = 0.005). Meta-analysis revealed no difference in odds of conduit ischemia (OR 0.40; 95% CI 0.13-1.23; I² = 0%; p = 0.11) and no difference in odds of overall survival (OR 0.54; 95% CI 0.29-1.02; I² = 22%; p = 0.06).

CONCLUSION

GIC is associated with reduced odds of anastomotic leaks and anastomotic strictures and may decrease morbidity in patients undergoing esophagectomy. Further prospective randomized trials are needed to better identify the optimal patient population, timing, and techniques used to best achieve GIC.

Are Esophagectomy Board Requirements Achievable? A Multi-Institutional Analysis

Duty-hour restrictions have implications on trainee operative exposure necessary to meet minimum case-volume requirements. We utilized a previously validated simulation model to evaluate the effect of program volume, trainee numbers and complement, and rotation schedule on the probability of achieving adequate esophagectomy case numbers for cardiothoracic surgery trainees. A ProModel simulator centered on probabilistic distributions of operative cases was utilized. Historical data from five 2-year cardiothoracic surgery training programs were obtained from 2016-2018 and used as inputs to the simulator that generated 10,000 "trainee 2-year periods" per program. Programs varied in annual average esophagectomy volume (12-91 per year), with 2-4 trainees graduating over a 2-year training period. If esophagectomy cases were distributed solely based on scheduling and institutional volume, only 60% of evaluated programs could adequately expose all trainees in esophagectomy to meet case requirements. The 3 programs with adequate esophagectomy volumes had averaged 3.3 times (range 3.0-3.6) the minimum number of board-required cases for their programs' trainees. The ability of programs to provide trainees with adequate esophagectomy volume is challenging based on institutional volume and scheduling. Through simulation, we demonstrate that programs need >2 times the expected minimum number of esophagectomies to ensure that >90% of trainees meet case-volume requirements. Programs may consider strategies such as allowing trainees to select cases based on personal need, train fewer fellows, or enable trainees to seek subspecialty exposure externally to achieve minimum esophagectomy case-load requirements.

Toward competency based continuing professional development for practicing surgeons

BACKGROUND

There has been a recent call for formal competency assessments of practicing physicians and surgeons to form a framework of competency based continuing professional development (CBCPD).

METHODS

An email questionnaire was conducted regarding CBCPD. Responses were further used to inform development of semi-structured interviews.

RESULTS

There were 58 questionnaire respondents (42%). There was moderate support for assessment of surgeons' technical skills (50.9%) or decision making (56.6%). Support was highest for a mechanism to flag surgeons in need of a focused competence assessment (83.0%). Eight surgeons participated in interviews. Interviews identified a range of benefits of CBCPD but also several challenges to implementation, including the need for fair, data-driven assessments, taking into account patient outcomes.

CONCLUSIONS

Through listening to surgeon concerns and recommendations for implementation strategies, this study's findings may support development of an effective CBCPD strategy with the potential to be embraced by surgeons and foster an environment of improved safety and performance.

Competency Assessment for Mediastinal Mass Resection and Thymectomy: Design and Delphi Review Process

OBJECTIVES

Mediastinal mass resection and thymectomy are complex and related operations that are core components of competency for a general thoracic surgeon and an important learning objective for thoracic surgery trainees. This study aimed to design a combined competency assessment instrument for mediastinal mass resection and thymectomy.

DESIGN

A comprehensive competency assessment instrument was designed by a process of logical analysis by 3 expert thoracic surgeons with an interest in mediastinal surgery. The instrument was then assessed and refined using a modified Delphi process.

SETTING

The Delphi questionnaire was distributed to all members of the Canadian Association of Thoracic Surgeons in 2018 to 2019.

PARTICIPANTS

The first round of the Delphi review was completed by 58 respondents (response rate 43.9%). Respondents represented all Canadian provinces with a wide range of clinical experience and a high rate of involvement in resident education.

RESULTS

A first draft of the competency assessment instrument included 42 steps in 6 categories. A total of 3 rounds of Delphi review were performed. Cronbach's alpha for the final round was 0.83. Ultimately, 29 items were retained from the original instrument and two modified and three new items were added. The final instrument has 34 steps in 5 categories.

CONCLUSIONS

A nationwide consensus was established on the key components of assessing competence to perform mediastinal mass resection and thymectomy. The resulting instrument could be used to guide competency based assessments of thoracic surgeons and trainees.

Automatic Referral for Potential Thoracic Malignant Diseases Detected on Computed Tomographic Scan

BACKGROUND

Delays in care negatively affect patients with potentially resectable thoracic malignant diseases. The Alberta Thoracic Oncology Program established an automatic referral process for patients with chest computed tomographic (CT) scans suggestive of malignant disease. The objective of this study was to determine whether automatic referral was associated with decreased time to referral or differences in the quality of referral information received.

METHODS

A single-center retrospective review of patients referred to a Canadian tertiary thoracic surgical center was performed. The time between the CT scan and the date of referral was calculated, and the type of information provided with the referral was tabulated. Automatic and traditional referral groups were compared using the Student t test, the Mann-Whitney U test, and multivariable analysis.

RESULTS

A total of 689 patients met inclusion criteria, and 405 of these patients were automatic referrals. Average time to referral was shorter in the automatic referral group (4.7 days vs 23.6 days; P < .001). Only 2 automatic referrals took longer than 30 days, compared with more than 25% of traditional referrals. Automatic referrals were always associated with a shorter time for referral on subgroup analysis of lung nodules, different referring physician types, and patient location. There was no difference between referral types in the number of referral data provided to the center.

CONCLUSIONS

Automatic referrals for patients with potential thoracic malignant disease have a significant beneficial impact on delays in care, and this could result in improved outcomes, such as decreased upstaging and improved survival. This was not associated with a decrease in the amount of information provided with the referral. Thus, automatic referrals may streamline patient care without compromising quality.

Diagnostic accuracy of sentinel lymph node biopsy using indocyanine green in lung cancer: a systematic review and meta-analysis

OBJECTIVE

The use of sentinel lymph node biopsy (SLNB) has been gaining popularity with the emergence of indocyanine green (ICG) fluorescence imaging. We aimed to systematically review the literature and perform a meta-analysis on the diagnostic accuracy of SLNB using ICG for lung cancer.

METHODS

A comprehensive search of MEDLINE, EMBASE, SCOPUS, Web of Science, and the Cochrane Library using search terms "lung/pulmonary" AND "tumor/carcinoma/cancer/neoplasm/adenocarcinoma/malignancy/squamous/carcinoid" AND "indocyanine green" was completed in June 2018. Articles were selected based on the following inclusion criteria: (1) diagnostic accuracy study design; (2) ICG injected at the tumor site with near-infrared fluorescence imaging identification of sentinel lymph nodes; (3) lymphadenectomy or sampling was performed as the gold standard.

RESULTS

Eight primary studies were included with a total of 366 patients. 43.0% of patients were females and the mean tumor size was 2.3 cm. Sentinel lymph nodes were identified with ICG in 251 patients, yielding a pooled identification rate of 0.83 (0.67-0.94). A meta-analysis of seven studies computed a diagnostic odds ratio, sensitivity, and specificity of 177.6 (45.6-691.1), 0.85 (0.71-0.94), and 1.00 (0.98-1.00), respectively. The summary receiver operator characteristic demonstrated an area under the curve of 0.963 (SE = 0.038) and a Q* of 0.91 (SE = 0.057).

CONCLUSION

Our review found suboptimal results for the diagnostic accuracy of SLNB using ICG and must be improved before routine clinical use. Further research is required to develop a robust protocol for the use SLNB with ICG for lung cancer.

A PXY-Mediated Transcriptional Network Integrates Signaling Mechanisms to Control Vascular Development in Arabidopsis

The cambium and procambium generate the majority of biomass in vascular plants. These meristems constitute a bifacial stem cell population from which xylem and phloem are specified on opposing sides by positional signals. The PHLOEM INTERCALATED WITH XYLEM (PXY) receptor kinase promotes vascular cell division and organization. However, how these functions are specified and integrated is unknown. Here, we mapped a putative PXY-mediated transcriptional regulatory network comprising 690 transcription factor-promoter interactions in Arabidopsis (Arabidopsis thaliana). Among these interactions was a feedforward loop containing transcription factors WUSCHEL HOMEOBOX RELATED14 (WOX14) and TARGET OF MONOPTEROS6 (TMO6), each of which regulates the expression of the gene encoding a third transcription factor, LATERAL ORGAN BOUNDARIES DOMAIN4 (LBD4). PXY signaling in turn regulates the WOX14, TMO6, and LBD4 feedforward loop to control vascular proliferation. Genetic interaction between LBD4 and PXY suggests that LBD4 marks the phloem-procambium boundary, thus defining the shape of the vascular bundle. These data collectively support a mechanism that influences the recruitment of cells into the phloem lineage, and they define the role of PXY signaling in this context in determining the arrangement of vascular tissue.

Development and Pilot Testing of an Assessment Tool for Performance of Anatomic Lung Resection

BACKGROUND

To meet the need for competency assessment in thoracic surgery education, we developed and tested an instrument to assess trainees' ability to perform anatomic lung resection for cancer.

METHODS

The Thoracic Competency Assessment Tool-Anatomic Resection for Lung Cancer (TCAT-ARC) was developed through a multistep process involving logical analysis, expert review, and simulation-based and clinical pilot testing. Validity evidence was gathered during a 6-month clinical study of trainees performing anatomic lung resections and assessments of practicing surgeons. Feedback was gathered via post-encounter questionnaires.

RESULTS

A 35-item instrument was developed and was tested in the clinical validation study. Seven trainees in 4 North American institutions participated and completed 64 anatomic lung resections. Reliability was high (α = 0.93). Interobserver reliability (k = 0.73) and correlation with an existing global competency scale (k = 0.68) were moderately high. Item analysis revealed the most difficult and discriminatory items, which matched well with a conceptual understanding of lung resection. Both trainees and assessors viewed the instrument as highly educationally effective and user-friendly. Practicing surgeons outperformed trainees.

CONCLUSIONS

The TCAT-ARC demonstrated early evidence of validity and reliability in assessing performance of anatomic lung resection. The instrument may be most useful early in training and as a means for providing fine-grained formative feedback about which steps have been mastered and which still require improvement. The TCAT-ARC may be used in training programs to aid in the development of trainees' competency and as a part of an aggregate assessment of trainees' overall mastery of the procedure and readiness for independent practice.

Attitudes of robotic surgery educators and learners: challenges, advantages, tips and tricks of teaching and learning robotic surgery

As the application of robotic surgical technology grows, so does the need to instruct surgical residents in robotic techniques. To better understand the challenges and benefits unique to robotic surgery education, this study explored the attitudes of teachers and learners. A 43-item questionnaire was developed with five domains: challenges and benefits of robotic education, training methodologies, trainees' readiness for learning, and education tips. This was delivered to surgeons and surgical fellows at a high-volume surgical department. 31 surgeons and 25 fellows from 7 specialties responded (response rate 70% and 43%). The teaching and learning of robotic surgery were perceived as superior to traditional minimally invasive surgery by both surgeons (in 7/9 factors studied) and fellows (7/9), but was seen as mostly disadvantageous compared to open surgery by both surgeons (in 6/9 factors studied) and fellows (8/9). Surgeons frequently stated the greatest challenge to teaching robotics was the need to relinquish total control to the trainee. Robotic surgery education is generally well received and offers several advantages. However, teaching robotic surgery presents unique challenges, especially when compared to open surgery. Understanding the benefits of, and barriers to, robotic surgery education may help develop more effective training paradigms that are responsive to educational needs while maintaining patient safety.

Organ-specific genetic interactions between paralogues of the PXY and ER receptor kinases enforce radial patterning in Arabidopsis vascular tissue

In plants, cells do not migrate. Tissues are frequently arranged in concentric rings; thus, expansion of inner layers is coordinated with cell division and/or expansion of cells in outer layers. In Arabidopsis stems, receptor kinases, PXY and ER, genetically interact to coordinate vascular proliferation and organisation via inter-tissue signalling. The contribution of PXY and ER paralogues to stem patterning is not known, nor is their function understood in hypocotyls, which undergo considerable radial expansion. Here, we show that removal of all PXY and ER gene-family members results in profound cell division and organisation defects. In hypocotyls, these plants failed to transition to true radial growth. Gene expression analysis suggested that PXY and ER cross- and inter-family transcriptional regulation occurs, but it differs between stem and hypocotyl. Thus, PXY and ER signalling interact to coordinate development in a distinct manner in different organs. We anticipate that such specialised local regulatory relationships, where tissue growth is controlled via signals moving across tissue layers, may coordinate tissue layer expansion throughout the plant body.

Development and Pilot Testing of an Assessment Tool for Performance of Invasive Mediastinal Staging

BACKGROUND

To develop and evaluate a surgical trainee competency assessment instrument for invasive mediastinal staging, including cervical mediastinoscopy and endobronchial ultrasound (EBUS), a comprehensive instrument was developed, the Thoracic Competency Assessment Tool-Invasive Staging (TCAT-IS), using expert review and simulated and clinical pilot-testing.

METHODS

Validity and reliability evidence were collected, and item analysis was performed. Initially, a 27-item instrument was developed, which underwent expert review with members of the Canadian Association of Thoracic Surgeons (n = 86) in 2014 to 2015 (response rate, 57%). TCAT-IS was refined to 29 items in 4 competency areas: preoperative, general operative, mediastinoscopy, and EBUS. Further refinements were made based on simulated use. The final version was then used to assess competency of 5 thoracic trainees performing invasive mediastinal staging in live patients.

RESULTS

Participants were assessed during 20 mediastinoscopy and 8 EBUS procedures, with 47 total assessments completed. Reliability (Cronbach's alpha = 0.94), interrater reliability (κ = 0.80), and correlation with an established global competency scale (κ = 0.75) were high. The most difficult items were "set up and adjust EBUS equipment" and "identify vascular anatomy (EBUS)." Feedback questionnaires from trainees (response rate, 80%) and surgeons (response rate, 100%) were consistently positive regarding user friendliness, utility as an assessment tool, and educational benefit. Participants believed the tool "facilitated communicating feedback to the trainee with specific areas to work on."

CONCLUSIONS

TCAT-IS is an effective tool for assessing competence in invasive staging and may enhance instruction. This initial test establishes early validity and reliability evidence, supporting the use of TCAT-IS in providing structured, specific, formative assessments of competency.

Is lobectomy superior to sublobar resection for early-stage small-cell lung cancer discovered intraoperatively?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: Is lobectomy superior to sublobar resection (SLR) for early-stage (cT1/2N0) small-cell lung cancer (SCLC) discovered intraoperatively? Altogether, more than 360 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Surgical treatment was shown to be superior to non-surgical treatment for early-stage SCLC in 8 papers. Seven papers showed that among patients treated surgically, lobectomy is associated with improved survival compared to SLR. One paper demonstrated both improved survival and improved freedom from local recurrence. However, 1 paper showed no difference when lobectomy was compared to anatomical segmentectomy. Three papers demonstrated significant rates of upstaging in surgical patients. Although both lobectomy and SLR are associated with improved survival compared with non-surgical treatment in early-stage SCLC, lobectomy is superior. Lobectomy was associated with improved median and overall survival, better upstaging and decreased local recurrence compared to SLR, although there is potential for selection bias and stage migration. Lobectomy should be considered the optimal approach for patients with early-stage SCLC.

Esophagectomy in a patient with double aortic arch and right descending aorta

We herein report the case of a 57-year-old man with esophageal cancer who was found to have a double aortic arch and right-sided descending aorta. Traditional approaches such as the Ivor Lewis and McKeown were excluded because the descending aorta would obscure the surgical field, and a neck anastomosis with the conduit through the ring could result in compression. We therefore opted for a left thoracoabdominal incision, allowing excellent exposure while reserving the possibility of placing the conduit substernally.

An essential role for abscisic acid in the regulation of xylem fibre differentiation

Division of the cambial cells and their subsequent differentiation into xylem and phloem drives radial expansion of the hypocotyl. Following the transition to reproductive growth, a phase change occurs in the Arabidopsis hypocotyl. During this second phase, the relative rate of xylem production is dramatically increased compared with that of phloem, and xylem fibres that contain thick secondary cell walls also form. Using two different genetic backgrounds and different environmental conditions, we identified a set of core transcriptional changes that is associated with the switch to the second phase of growth in the hypocotyl. Abscisic acid (ABA) signalling pathways are significantly over-represented in this set of core genes. Reverse genetic analysis demonstrated that mutants that are defective in ABA-biosynthesis enzymes exhibited significantly delayed fibre production without affecting the xylem:phloem ratio, and that these effects can be reversed by the application of ABA. The altered morphology is also reflected at the transcript level, with a reduced expression of marker genes that are associated with fibre formation in aba1 mutants. Taken together, the data reveal an essential role for ABA in the regulation of fibre formation.

The Role of Intraoperative Fluorescence Imaging During Esophagectomy

Intraoperative fluorescence imaging (FI) with indocyanine green has several potential uses during esophagectomy. Intravascular injection for enhancing the visualization of conduit vascularity and assessing macro and microperfusion has the most literature support and may help reduce anastomotic leaks. Peritumoral injection has been reported for use in identifying sentinel nodes during lymphadenectomy and intralymphatic injection may be used to help preserve or ligate the thoracic duct. The authors' own technique of FI for conduit assessment is described. They routinely use this strategy to guide anastomosis placement and reduce leaks.

Feasibility of endobronchial ultrasound transbronchial needle aspiration for massively parallel next-generation sequencing in thoracic cancer patients

INTRODUCTION

Next-generation sequencing (NGS) allows for the identification of a growing number of therapeutic and prognostic molecular targets. However, NGS typically requires greater quantities of DNA than traditional molecular testing does. Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure used to sample central thoracic lesions, but it is not well established whether this technique provides sufficient material for NGS.

METHODS

We performed a retrospective review of EBUS-TBNA at our institution (3/1/14-9/28/16). NGS was performed using a comprehensive hybrid-capture based assay (MSK-IMPACT) that detects >340 gene mutations. Samples found to be diagnostic for malignancy and for which MSK-IMPACT had been attempted were identified. Pathologic and clinical data were obtained from the medical record, and the results of MSK-IMPACT were examined.

RESULTS

In total, 784 EBUS-TBNA procedures were performed during the study period. MSK-IMPACT was requested for 115 malignant samples and was successful for 99 (86.1%), identifying an average of 12.7 mutations at a mean coverage depth of 806X. NGS was performed on paraffin-embedded cell blocks in 93 cases (93.9%) and on cell-free DNA in needle rinse fluid in 6 cases. The success rate of the assay improved significantly from the first third of cases (76.3%), to 92.3% for the final one-third of cases (p < 0.05).

CONCLUSIONS

EBUS-TBNA reliably provided adequate tissue for hybrid capture NGS, and is a suitable option for comprehensive NGS testing in patients with thoracic malignancies.

Patterns of Practice in Mediastinal Lymph Node Staging for Non-Small Cell Lung Cancer in Canada

BACKGROUND

Assessment of mediastinal lymph nodes is integral in staging patients with non-small cell lung cancer (NSCLC). This study delineated the lymph node staging practices of Canadian thoracic surgeons in patients with potentially resectable NSCLC.

METHODS

A questionnaire was distributed to Canadian Association of Thoracic Surgeons members (n = 86). Items addressed the use of imaging, thresholds/methods for preoperative invasive staging, and intraoperative node staging. Comparison was made against Canadian, American, and European guidelines.

RESULTS

Forty-seven surgeons (55%) responded. Although most stated they derived practices from published guidelines, a significant proportion did not reflect those recommendations. Most respondents ordered a positron emission tomography scan for every patient (87.2%), and the same proportion (87.2%) performed invasive staging selectively, with a wide range of indications. The most common thresholds were suspicious nodes on imaging (80.5%), tumor within the central third of the lung (67.5%), and tumor exceeding 3 cm (34.2%). Endobronchial ultrasound, alone or with endoscopic ultrasound, was selected as the initial staging procedure of choice by 47.9%, and 43.5% selected mediastinoscopy first. Of surgeons selecting mediastinoscopy, 61.9% reported some barriers to performing endobronchial ultrasound. There was variability, between surgeons and between lobes, in which nodes respondents harvested intraoperatively for given lobectomies. A sizeable minority (13%) did not routinely harvest lymph nodes intraoperatively.

CONCLUSIONS

Determining the appropriate treatment and prognosis of NSCLC patients relies on proper staging. Significant variability exists in node staging practices in Canada as well as divergence from guidelines. This may result in understaging or overstaging patients and inappropriate care.