Bilateral sequential lung transplantation: technical aspects

Poststernotomy Imaging: Pictorial Review of Expected Postsurgical Findings and Complications

Sternotomy is a widely used incision technique in cardiac and thoracic surgeries. Multiple sternotomy techniques exist, such as the Robicsek technique for redo sternotomy and transverse (clamshell) thoracosternotomy for bilateral lung transplantation. Various complications after sternotomy can occur, and imaging plays a key role in their identification. Complications may involve the hardware, sternum, and peristernal soft tissues and are divided into acute, subacute, and late. Acute complications primarily involve hemorrhage and dehiscence, while subacute complications include superficial or deep sternal wound infections and late complications are typically osseous or hardware related. Imaging also plays a critical role in assessment of cardiovascular structures and their relations to the sternum in those undergoing redo sternotomy, which has become increasingly performed. CT allows radiologists to identify the relationship of vascular anatomy to the sternum as well as other factors that may complicate repeat surgery, allowing surgeons to strategize safe surgical approaches. ©RSNA, 2025 Supplemental material is available for this article.

Comparability of Quantifying Relative Lung Ventilation with Inhaled 99mTc-Technegas and 133Xe in Patients Undergoing Evaluation for Lung Transplantation

99mTc-Technegas was recently approved by the U.S. Food and Drug Administration as a radiopharmaceutical for ventilation scintigraphy. However, there are currently no data comparing the quantification of relative lung ventilation with 99mTc-Technegas with that performed using the standard approach with inhaled 133Xe. Methods: We performed a secondary analysis of data from prospectively recruited participants in a phase 3 trial undergoing evaluation for lung transplantation who received both 133Xe and 99mTc-Technegas ventilation imaging. The 133Xe and 99mTc-Technegas images were analyzed asynchronously using semiautomatic segmentation to extract the relative lung ventilation percentages. The anterior and posterior 99mTc-Technegas images were analyzed to derive 3 sets of relative ventilation percentages (posterior, anterior, and geometric mean data) and compared with the values from posterior 133Xe images. We evaluated for correlation and agreement between the relative lung ventilation percentages obtained using these 2 radiopharmaceuticals. Results: In a cohort of 74 participants, we found a strong positive correlation in the relative lung ventilation quantified using 133Xe with that using 99mTc-Technegas. A high level of agreement was demonstrated on the Bland-Altman plot comparing the 2 imaging modalities. Seventy-two of 74 participants (97.3%) had their relative ventilation percentage measurements within ±15% for 133Xe and 99mTc-Technegas. The differences in relative ventilation measurements were within the 95% CI limits of the mean for 70 of 74 participants (94.6%) and within a narrower ±10% threshold for 68 of 74 participants (91.9%), again reflecting the comparability of the 2 techniques. The strongest correlation coefficient (r = 0.79) was observed between the relative ventilation percentages obtained from 133Xe and posterior 99mTc-Technegas images. The geometric mean method had a slightly lower but still comparable correlation (r = 0.77), and as expected, the correlation with the anterior 99mTc-Technegas images was worst (r = 0.70). Conclusion: We showed a strong positive correlation and high agreement between the relative lung ventilation percentages obtained using 133Xe and 99mTc-Technegas. These data provide important clinical evidence supporting the use of 99mTc-Technegas for quantification of relative lung ventilation.

Current status of routine use of veno-arterial extracorporeal membrane oxygenation during lung transplantation

INTRODUCTION

Recently, there has been growing experience with utilizing a veno-arterial extracorporeal membrane oxygenator (VA ECMO) routinely during lung transplantation procedures. Yet, there is a lack of consensus on the protocols, benefits, and outcomes of routine VA ECMO use in lung transplantation.

AREAS COVERED

This article presents an overview of the current status of routine use of VA ECMO during lung transplantation, including rationale, protocols, applications, and outcomes.

EXPERT OPINION

Utilization of VA ECMO during lung transplantation has emerged as an alternative mechanical circulatory support modality to cardiopulmonary bypass, with growing evidence showing lower rates of peri-operative complications. Some groups took that further into routine application of VA ECMO during lung transplantation. The current available evidence suggests that routine utilization of VA ECMO during lung transplantation is associated with lower rates of primary graft dysfunction and improved early outcomes. Use of VA ECMO allows controlled reperfusion of the allograft and avoids an unplanned "crash" on pump in case of hemodynamic instability, which carries worse outcomes after lung transplantation. As a relatively new approach, further follow-up of growing experience, as well as prospective clinical trials, is necessary to develop a consensus about routine utilization of VA ECMO during lung transplantation.

Comparing right- versus left-first implantation in off-pump sequential double-lung transplantation: an observational cohort study

OBJECTIVES

Historically, the perfusion-guided sequence suggests to first transplant the side with lowest lung perfusion. This sequence is thought to limit right ventricular afterload and prevent acute heart failure after first pneumonectomy. As a paradigm shift, we adopted the right-first implantation sequence, irrespective of lung perfusion. The right donor lung generally accommodates a larger proportion of the cardiac output. We hypothesized that the right-first sequence reduces the likelihood of oedema formation in the firstly transplanted graft during second-lung implantation. Our objective was to compare the perfusion-guided and right-first sequence for intraoperative extracorporeal membrane oxygenation (ECMO) need and primary graft dysfunction (PGD).

METHODS

A retrospective single-centre cohort study (2008-2021) including double-lung transplant cases (N = 696) started without ECMO was performed. Primary end-points were intraoperative ECMO cannulation and PGD grade 3 (PGD3) at 72 h. Secondary end-points were patient and chronic lung allograft dysfunction-free survival. In cases with native left lung perfusion ≤50% propensity score adjusted comparison of the perfusion-guided and right-first sequence was performed.

RESULTS

When left lung perfusion was ≤50%, right-first implantation was done in 219 and left-first in 189 cases. Intraoperative escalation to ECMO support was observed in 10.96% of right-first versus 19.05% of left-first cases (odds ratio 0.448; 95% confidence interval 0.229-0.0.878; P = 0.0193). PGD3 at 72 h was observed in 8.02% of right-first versus 15.64% of left-first cases (0.566; 0.263-1.217; P = 0.1452). Right-first implantation did not affect patient or chronic lung allograft dysfunction-free survival.

CONCLUSIONS

The right-first implantation sequence in off-pump double-lung transplantation reduces need for intraoperative ECMO cannulation with a trend towards less PGD grade 3.

Risk factors and clinical consequences of early extubation failure in lung transplant recipients

Background

Prolonged intubation following lung transplantation is thought to delay recovery, yet a paucity of data exists regarding risk factors and outcomes related to extubation failure.

Methods

We performed a single-center, retrospective analysis of 238 lung transplant recipients between January 1, 2018, and December 31, 2022, to identify risk factors for extubation failure (intubation greater than 3 days, reintubation, and/or need for tracheostomy). We also assessed short-term outcomes relative to extubation success.

Results

In this cohort, 144 patients (60%) were extubated successfully while 94 patients experienced extubation failure; 10 (11%) were intubated greater than 3 days, 9 (9%) were reintubated, 34 (36%) required tracheostomy after reintubation, and 41 (44%) underwent empiric tracheostomy. Recipient height and female sex, lung allocation score, 6-minute walk distance, donor ischemic time, ex-vivo perfusion, donor smoking history, intraoperative transfused red blood cells (packed red blood cells (PRBCs)), primary graft dysfunction at time zero, and comatose sedation state at day 2 were associated with extubation failure on univariate analysis (all p < 0.01), whereas comatose state [(odds ratio) OR = 84.95 (95%confidence interval (CI) 17-423), p < 0.01], donor smoking [OR = 5.41 (95%CI 1.73-16.92), p < 0.01], primary graft dysfunction at T0 [OR = 2.02 (95%CI 1.22-3.34), p < 0.01], and PRBCs [OR = 1.19 (95%CI 1.06-1.34, p < 0.01] were independently associated with extubation failure on multivariate analysis. Reintubation and empiric tracheostomy were associated with similarly prolonged intensive care unit and hospital length of stay, while tracheostomy was also associated with protracted inpatient rehabilitation, increased functional impairment, and increased 6-month mortality.

Conclusions

Specific baseline donor and recipient demographics and intraoperative variables are associated with greater risk for post-transplant extubation failure. Patients with extubation failure have worse short-term outcomes.

Risk factors associated with surgical site infections in patients undergoing cardiothoracic surgery: A systematic review and meta-analysis

Surgical site infections (SSIs) following cardiothoracic surgery can pose significant challenges to patient recovery and outcome. This systematic review and meta-analysis aim to identify and quantify the risk factors associated with SSIs in patients undergoing cardiothoracic surgery. A comprehensive literature search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and based on the PICO paradigm was conducted across four databases: PubMed, Embase, Web of Science and the Cochrane Library, without any temporal restrictions. The meta-analysis incorporated studies detailing the risk factors for post-operative sternal infections, especially those reporting odds ratios (OR) or relative risks with 95% confidence intervals (CI). Quality assessment of the studies was done using the Newcastle-Ottawa Scale. Statistical analysis was executed using the chi-square tests for inter-study heterogeneity, with further analyses depending on I2 values. Sensitivity analyses were performed, and potential publication bias was also assessed. An initial dataset of 2442 articles was refined to 21 articles after thorough evaluations based on inclusion and exclusion criteria. Patients with diabetes mellitus have an OR of 1.80 (95% CI: 1.40-2.20) for the incidence of SSIs, while obese patients demonstrate an OR of 1.63 (95% CI: 1.40-1.87). Individuals who undergo intraoperative blood transfusion present an OR of 1.13 (95% CI: 1.07-1.18), and smokers manifest an OR of 1.32 (95% CI: 1.03-1.60). These findings unequivocally indicate a pronounced association between these factors and an elevated risk of SSIs post-operatively. This meta-analysis confirms that diabetes, obesity, intraoperative transfusion and smoking heighten the risk of SSIs post-cardiac surgery. Clinicians should be alert to these factors to optimise patient outcomes.

Lung Transplantation for Pulmonary Artery Hypertension

This manuscript discusses the role of lung transplantation in patients with pulmonary hypertension. The indications and timing for referral to a transplant unit and timing for wait-listing for lung transplantation are discussed. The type of transplantation—isolated (single or double) lung transplantation and situations when combined heart and double lung transplantation is indicated—will be elaborated. Escalation of medical therapy with the need and timing for bridging therapies such as extracorporeal membrane oxygenation until an appropriate organ becomes available will be discussed. Challenges in the postoperative period, specific to lung transplantation for pulmonary artery hypertension, will be reviewed. The outcomes following lung transplantation will also be considered in greater detail.