Impact of sex on outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

The impact of sex on long-term outcomes after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (PH) remains unclear. We therefore examined the early and long-term outcome after PEA to determine whether sex had an impact on the risk of residual PH and need for targeted PH medical therapy.

METHODS

Retrospective study of 401 consecutive patients undergoing PEA at our institution between August 2005 and March 2020 was performed. Primary outcome was the need for targeted PH medical therapy postoperatively. Secondary outcomes included survival and measures of hemodynamic improvement.

RESULTS

Females (N = 203, 51%) were more likely to have preoperative home oxygen therapy (29.6% vs 11.6%, p < 0.01), and to present with segmental and subsegmental disease compared to males (49.2% vs 21.2%, p < 0.01). Despite similar preoperative values, females had higher postoperative pulmonary vascular resistance (final total pulmonary vascular resistance after PEA, 437 Dynes∙s∙cm-5 vs 324 Dynes∙s∙cm-5 in males, p < 0.01). Although survival at 10 years was not significantly different between sexes (73% in females vs 84% in males, p = 0.08), freedom from targeted PH medical therapy was lower in females (72.9% vs 89.9% in males at 5 years, p < 0.001). Female sex remained an independent factor affecting the need for targeted PH medical therapy after PEA in multivariate analysis (HR 2.03, 95%CI 1.03-3.98, p = 0.04).

CONCLUSIONS

Although outcomes are excellent for both sexes, females had greater need for targeted PH medical therapy in the long-term. Early reassessment and long-term follow-up of these patients are important. Further investigations into possible mechanisms to explain the differences are warranted.

A machine-learning approach to human ex vivo lung perfusion predicts transplantation outcomes and promotes organ utilization

Ex vivo lung perfusion (EVLP) is a data-intensive platform used for the assessment of isolated lungs outside the body for transplantation; however, the integration of artificial intelligence to rapidly interpret the large constellation of clinical data generated during ex vivo assessment remains an unmet need. We developed a machine-learning model, termed InsighTx, to predict post-transplant outcomes using n = 725 EVLP cases. InsighTx model AUROC (area under the receiver operating characteristic curve) was 79 ± 3%, 75 ± 4%, and 85 ± 3% in training and independent test datasets, respectively. Excellent performance was observed in predicting unsuitable lungs for transplantation (AUROC: 90 ± 4%) and transplants with good outcomes (AUROC: 80 ± 4%). In a retrospective and blinded implementation study by EVLP specialists at our institution, InsighTx increased the likelihood of transplanting suitable donor lungs [odds ratio=13; 95% CI:4-45] and decreased the likelihood of transplanting unsuitable donor lungs [odds ratio=0.4; 95%CI:0.16-0.98]. Herein, we provide strong rationale for the adoption of machine-learning algorithms to optimize EVLP assessments and show that InsighTx could potentially lead to a safe increase in transplantation rates.

Association of Circulating Tumor DNA Testing Before Tissue Diagnosis With Time to Treatment Among Patients With Suspected Advanced Lung Cancer: The ACCELERATE Nonrandomized Clinical Trial

Importance

Liquid biopsy has emerged as a complement to tumor tissue profiling for advanced non-small cell lung cancer (NSCLC). The optimal way to integrate liquid biopsy into the diagnostic algorithm for patients with newly diagnosed advanced NSCLC remains unclear.

Objective

To evaluate the use of circulating tumor DNA (ctDNA) genotyping before tissue diagnosis among patients with suspected advanced NSCLC and its association with time to treatment.

Design, Setting, and Participants

This single-group nonrandomized clinical trial was conducted among 150 patients at the Princess Margaret Cancer Centre-University Health Network (Toronto, Ontario, Canada) between July 1, 2021, and November 30, 2022. Patients referred for investigation and diagnosis of lung cancer were eligible if they had radiologic evidence of advanced lung cancer prior to a tissue diagnosis.

Interventions

Patients underwent plasma ctDNA testing with a next-generation sequencing (NGS) assay before lung cancer diagnosis. Diagnostic biopsy and tissue NGS were performed per standard of care.

Main Outcome and Measures

The primary end point was time from referral to treatment initiation among patients with advanced nonsquamous NSCLC using ctDNA testing before diagnosis (ACCELERATE [Accelerating Lung Cancer Diagnosis Through Liquid Biopsy] cohort). This cohort was compared with a reference cohort using standard tissue genotyping after tissue diagnosis.

Results

Of the 150 patients (median age at diagnosis, 68 years [range, 33-91 years]; 80 men [53%]) enrolled, 90 (60%) had advanced nonsquamous NSCLC. The median time to treatment was 39 days (IQR, 27-52 days) for the ACCELERATE cohort vs 62 days (IQR, 44-82 days) for the reference cohort (P < .001). Among the ACCELERATE cohort, the median turnaround time from sample collection to genotyping results was 7 days (IQR, 6-9 days) for plasma and 23 days (IQR, 18-28 days) for tissue NGS (P < .001). Of the 90 patients with advanced nonsquamous NSCLC, 21 (23%) started targeted therapy before tissue NGS results were available, and 11 (12%) had actionable alterations identified only through plasma testing.

Conclusions and Relevance

This nonrandomized clinical trial found that the use of plasma ctDNA genotyping before tissue diagnosis among patients with suspected advanced NSCLC was associated with accelerated time to treatment compared with a reference cohort undergoing standard tissue testing.

Trial Registration

ClinicalTrials.gov Identifier: NCT04863924.

Rapid Prototyping Techniques for the Development of a Take-Home Surgical Anastomosis Simulation Model

OBJECTIVE

The objective of this paper is to describe the techniques and process of developing and testing a take-home surgical anastomosis simulation model.

DESIGN

Through an iterative process, a simulation model was customized and designed to target specific skill development and performance objectives that focused on anastomotic techniques in thoracic surgery and consist of 3D printed and silicone molded components. Various manufacturing techniques such as silicone dip spin coating and injection molding have been described in this paper and explored as part of the research and development process. The final prototype is a low-cost, take-home model with reusable and replaceable components.

SETTING

The study took place at a single-center quaternary care university-affiliated hospital.

PARTICIPANTS

The participants included in the model testing were 10 senior thoracic surgery trainees who completed an in-person training session held during an annual hands- on thoracic surgery simulation course. Feedback was then collected in the form of an evaluation of the model from participants.

RESULTS

All 10 participants had an opportunity to test the model and complete at least 1 pulmonary artery and bronchial anastomosis. The overall experience was rated highly, with minor feedback provided regarding the set- up and fidelity of the materials used for the anastomoses. Overall, the trainees agreed that the model was suitable for teaching advanced anastomotic techniques and expressed an interest in being able to use this model to practice skill development.

CONCLUSIONS

Developed simulation model can be easily reduced, with customized components that accurately simulate real-life vascular and bronchial components suitable for training of anastomoses technique amongst senior thoracic surgery trainees.

Osteosarcoma emboli presenting as chronic thromboembolic pulmonary hypertension in a child

A 13-year-old girl presented with hypoxemia during adjuvant chemotherapy for an osteosarcoma of the left distal femur. She underwent an amputation complicated by a post-operative pulmonary embolism (PE). Three months post-operatively, she was admitted to hospital with severe hypoxemia and diagnosed with pulmonary hypertension on echocardiogram in the context of extensive bilateral PE on computed tomography. She was planned for elective pulmonary thromboendarterectomy, but rapidly deteriorated requiring emergent surgery. At the time of surgery, she was found to have extensive tumor emboli throughout both pulmonary arteries. She recovered well post-operatively but died 2 months later from progressive disease.

Plasma-first: accelerating lung cancer diagnosis and molecular profiling through liquid biopsy

Introduction:

Molecular profiling of tumor tissue is the gold standard for treatment decision-making in advanced non-small cell lung cancer (NSCLC). Results may be delayed or unavailable due to insufficient tissue, prolonged wait times for biopsy, pathology assessment and testing. We piloted the use of plasma testing in the initial diagnostic workup for patients with suspected advanced lung cancer.

Methods:

Patients with ⩽15 pack-year smoking history and suspected advanced lung cancer referred to the lung cancer rapid diagnostic program underwent plasma circulating-tumor DNA testing using a DNA-based mutation panel. Tissue testing was performed per standard of care, including comprehensive next-generation sequencing (NGS). The primary endpoint was time from diagnostic program referral to cancer treatment in stage IV NSCLC patients (Cohort A) compared to a contemporary cohort not enrolled in the study (Cohort B) and an historical pre-COVID cohort referred to the program between 2018 and 2019 (Cohort C).

Results:

From January to June 2021, 20 patients were enrolled in Cohort A; median age was 70.5 years (range 33–87), 70% were female, 55% Caucasian, 85% never smokers, and 75% were diagnosed with NSCLC. Seven had actionable alterations detected in plasma or tissue (4/7 concordant). Fusions, not tested in plasma, were identified by immunohistochemistry for three patients. Mean result turnaround time was 17.8 days for plasma NGS and 23.6 days for tissue (p = 0.10). Mean time from referral to treatment initiation was significantly shorter in cohort A at 32.6 days (SD 13.1) versus 62.2 days (SD 31.2) in cohort B and 61.5 days (SD 29.1) in cohort C, both p < 0.0001.

Conclusion:

Liquid biopsy in the initial diagnostic workup of patients with suspected advanced NSCLC can lead to faster molecular results and shorten time to treatment even with smaller DNA panels. An expansion study using comprehensive NGS plasma testing with faster turnaround time is ongoing (NCT04862924).

Maintaining technical proficiency in senior surgical fellows during the COVID-19 pandemic through virtual teaching

Objectives

The novel coronavirus (COVID-19) pandemic resulted in a severe reduction in operative opportunities for trainees. We hypothesized that augmenting independent practice with a bench model of vascular anastomoses using regular videoconferences and individual feedback would provide meaningful benefit in maintenance of technical skills in senior lung transplant surgical fellows.

Methods

A lung transplantation virtual technical skills course was developed. Surgical fellows were provided with a bench model and surgical instruments. Using a virtual communication platform, teaching sessions were held twice weekly, and fellows performed an anastomosis on camera. Video recordings were reviewed and critiqued by attending staff. At the end of the 3-month course, participants were surveyed about their experience. Warm ischaemic time was compared between fellows' five most recent cases before and after the pandemic.

Results

Seven senior surgical fellows participated and provided feedback. Fellows had graduated medical school an average of 14 years prior to fellowship, and spent an average of 5 hours (range 1.3 - 15 hours) of home practice. Five of seven (71%) participants reported improvement in their technical skills and increased confidence in performing a lung transplant. No significant difference in warm ischaemic time in procedures performed by fellows was identified (70.3 minutes pre-pandemic vs. 68.3 minutes post pandemic, p = 0.68).

Conclusions

A program of virtual technical skills teaching, individual video coaching, and independent practice provided benefit in maintaining technical skills in lung transplant surgical fellows during the COVID-19 pandemic, when equivalent operative experience was unavailable. Lessons learned from this exceptional time can be used to create simulation curricula for senior trainees.

CT-guided microcoil VATS resection of lung nodules: a single-centre experience and review of the literature

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) is standard of care for small lung resections at many centres. Computed tomography (CT)-guided insertion of microcoils can aid surgeons in performing VATS resections for non-palpable lung nodules deep to the lung surface.

METHODS

Retrospective analysis of CT-guided microcoil insertions prior to VATS lung resection at a single institution from October 2008 to January 2014.

RESULTS

A total of 63 patients were included (37% male, mean age 61.6±11.4 years). Forty-two patients (67%) had a history of smoking, with 10 current smokers. Sixty one (97%) patients underwent wedge resection and 3 (5%) patients had segmentectomy. Three (5%) patients required intra-operative staple line re-resection for positive or close margins. Eleven (17%) patients had a completion lobectomy, 5 of which were during the same anaesthetic. The average time between the CT-guided insertion and start of operation was 136.6±89.0 min, and average operative time was 84.0±53.3 min. The intra-operative complication rate was 5% (n=3), including 1 episode of hemoptysis, and 2 conversions to thoracotomy. The post-operative complication rate was 8% (5 patients), and included 2 air leaks, 1 hemothorax (drop in hemoglobin), 1 post chest tube removal pneumothorax, and one venous infarction of the lingula after lingula-sparing lobectomy requiring completion lobectomy. . Average post-operative length of stay was 2.2 days. A diagnosis was made for all patients.

CONCLUSIONS

CT-guided microcoil insertion followed by VATS lobectomy is safe, with short operative times, short length of stay and 100% diagnosis of small pulmonary nodules. This technique will become more important in the future with increasing numbers of small nodules detected on CT as part of lung cancer screening programs.