Anatomical variations in lymphatic drainage of the right lung: applications in lung cancer surgery

A comparative study of indocyanine green instillation in inguinal node versus foot web space using da Vinci indocyanine green FireFly™ technology in identifying thoracic duct during robotic-assisted transthoracic oesophagectomy

INTRODUCTION

Chyle leak is a serious complication following oesophagectomy with incidence varies from 1% to 9%. Near infra-red fluorescence imaging of thoracic duct (TD) can provide real-time dynamic imaging during the surgery. In this study, we intend to compare indocyanine green (ICG) dye instillation through inguinal node with subcutaneous first web space instillation for visualisation of TD during robotic-assisted minimally invasive oesophagectomy (RAMIE) procedure.

PATIENTS AND METHODS

A prospective study of 50 patients underwent RAMIE with da Vinci X System. After general anaesthesia, patients were divided into inguinal node and foot first web space ICG instillation group. The former group had 1 ml of ICG dye instilled on bilateral inguinal nodes under ultrasound guidance and while the other group received 1 mL of ICG dye injected at bilateral foot first web space and then underwent surgery. TD was visualised using ICG FireFly™ fluorescence technology, first at the time of docking and subsequently for every 5 min until 60 min of instillation time and analysed.

RESULTS

Twenty-five patients were enrolled in each group. The mean docking time for thoracic phase was 13.76 ± 3.43 min. TD was visualised in 72% (18/25) of cases of first web space instillation group, whereas 100% in ultrasound guidance inguinal node instillation group. None of the patients had a chyle leak.

CONCLUSION

ICG FireFly™ fluorescence technology for the identification of TD during oesophageal mobilisation is safe and effective and provides real-time dynamic visualisation with high accuracy in ultrasound-guided bilateral inguinal node instillation group. It is an effective method for the surgeons planning to negotiate their initial learning curve in RAMIE procedures.

An in silico approach to understanding the interaction between cardiovascular and pulmonary lymphatic dysfunction

The lung is extremely sensitive to interstitial fluid balance, yet the role of pulmonary lymphatics in lung fluid homeostasis and its interaction with cardiovascular pressures is poorly understood. In health, there is a fine balance between fluid extravasated from the pulmonary capillaries into the interstitium and the return of fluid to the circulation via the lymphatic vessels. This balance is maintained by an extremely interdependent system governed by pressures in the fluids (air and blood) and tissue (interstitium), lung motion during breathing, and the permeability of the tissues. Chronic elevation in left atrial pressure (LAP) due to left heart disease increases the capillary blood pressure. The consequent fluid accumulation in the delicate lung tissue increases its weight, decreases its compliance, and impairs gas exchange. This interdependent system is difficult, if not impossible, to study experimentally. Computational modeling provides a unique perspective to analyze fluid movement in the cardiopulmonary vasculature in health and disease. We have developed an initial in silico model of pulmonary lymphatic function using an anatomically structured model to represent ventilation and perfusion and underlying biophysical laws governing fluid transfer at the interstitium. This novel model was tested against increased LAP and noncardiogenic effects (increased permeability). The model returned physiologically reasonable values for all applications, predicting pulmonary edema when LAP reached 25 mmHg and with increased permeability.NEW & NOTEWORTHY This model presents a novel approach to understanding the interaction between cardiac dysfunction and pulmonary lymphatic function, using anatomically structured models and biophysical equations to estimate regional variation in fluid transport from blood to interstitial and lymphatic flux. This fluid transport model brings together advanced models of ventilation, perfusion, and lung mechanics to produce a detailed model of fluid transport in health and various altered pathological conditions.

Potential factors of cytokeratin fragment 21-1 and cancer embryonic antigen for mediastinal lymph node metastasis in lung cancer

Objective: Lung cancer is a common malignant tumor, characterized by being difficult to detect and lacking specific clinical manifestations. This study aimed to find out the risk factors of mediastinal lymph node metastasis and explore the correlation between serum tumor markers and mediastinal lymph node metastasis and lung cancer prognosis.

Methods: A retrospective study of 3,042 lung cancer patients (330 patients with mediastinal lymph node metastasis and 2,712 patients without mediastinal lymph node metastasis) collected from the First Affiliated Hospital of Nanchang University from April 1999 to July 2020. The patients were divided into two groups, namely, mediastinal lymph node metastasis group and non-mediastinal lymph node metastasis group. Student’s t test, non-parametric rank sum test and chi-square test were used to describe whether there is a significant difference between the two groups. We compared the serum biomarkers of the two groups of patients, including exploring serum alkaline phosphatase (ALP), calcium hemoglobin (HB), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), CA125, CA-199, CA -153, cytokeratin fragment 19 (CYFRA 21-1), total prostate specific antigen (TPSA), neuron-specific enolase (NSE) levels and the incidence and prognosis of lung cancer mediastinal lymph node metastasis. Binary logistic regression analysis was used to determine its risk factors, and receiver operating curve (ROC) analysis was used to evaluate its diagnostic value for mediastinal lymph node metastasis.

Results: Binary logistic regression analysis showed that carcinoembryonic antigen and CYFRA 21-1 were independent risk factors for mediastinal lymph node metastasis in patients with lung cancer (p < 0.001 and p = 0.002, respectively). The sensitivity and specificity of CEA for the diagnosis of mediastinal lymph node metastasis were 90.2 and 7.6%, respectively; CYFRA 21-1 were 0.6 and 99.0%, respectively.

Conclusion: Serum CEA and CYFRA 21-1 have predictive value in the diagnosis of mediastinal lymph node metastasis in patients with lung cancer.

Postmortem Retrograde Contrasted Infusion in Thoracic Duct Outflow: Imaging Effectiveness Analysis

Background

Thoracic duct (TD) anomaly can be quite variable and dangerous in surgical interventions in the neck region as there are numerous variations in its formation and topography. This highlights the importance of full knowledge about the TD and its anatomical variations. Thus, it is important to emphasize that the lack of anatomical-clinical knowledge or surgical skill during an intervention can significantly hamper successful results. The present study aimed to perform radiopaque contrast infusion into the TD of intact cadavers, either formalinized or refrigerated, to evaluate possible lymphatic architecture patterns via reverse lymphography.

Methodology

TD dissection was performed on 13 cadaveric specimens. After isolating the lymphatic vessel, it was cannulated with an nº 4 urethral probe fixed with cordonnet cotton. Then, a 10 mL syringe was attached to the urethral probe and the radiopaque iodinated contrast was injected into the TD under constant and gradual manual pressure.

Results

TD outflow was detected on the posterior surface of the junction between the internal jugular and the left subclavian veins, either as direct outflow (in 10 cases) or as an arc (in three cases). Reverse contrast progression was impossible in each of the attempts, probably due to valvular resistance and lumen obliteration, which completely prevented pressure infusion into the thoracic and abdominal parts of the TD.

Conclusions

We emphasize the impracticality of obtaining postmortem radiopaque images via retrograde contrast injection into the TD in formalinized or refrigerated bodies.

Lymphatic drainage of lung cancer follows an intersegmental pathway within the visceral pleura

OBJECTIVES

Lung cancer tumors are known to be highly lymphophilic. There are two different pattern of lymphatic drainage of the lung: one peribronchial lymphatic pathway, and another one within the visceral pleura which appears to be more intersegmental than the peribronchial pathway. We aimed to assess the prevalence of an intersegmental pathway in the lymphatic drainage of lung tumors within the visceral pleura and determine potential influential factors.

METHODS

In this prospective study, we included all patients for whom a major pulmonary resection (lobar) was indicated and performed for suspected or proven lung cancer. An immediate ex-vivo evaluation of the surgical specimen after resection was conducted by trans-pleural injection of blue dye within the tumor. The pathways followed by the lymphatic vessels under the visceral pleura were assessed to define the occurrence of an intersegmental pathway, which was defined by the presence of blue dye within the lymphatic vessel crossing to a neighboring pulmonary segment, distinct from the tumorous segment.

RESULTS

Fifty-three patients met the inclusion criteria and were assessed over a three-year period. Lymphatic drainage within the visceral pleura followed an intersegmental pathway in 35 of 53 patients (66 %). When the lymphatic drainage of the tumor was intersegmental, it drained in a single other segment in 21/35 cases and two or more in 14/35 cases. Logistic regression with multivariate analysis showed a peripheral location of the tumor to be a risk factor for the intersegmental pathway of visceral pleura lymphatic drainage (OR = 0.87 [079-0.95], p = 0.003).

CONCLUSION

These results confirm that lymphatic drainage of lung cancer in the visceral pleura appears to largely follow an intersegmental pathway, especially when the tumor is peripheral, close to the visceral pleura.

Anatomical variations and evolution: re-evaluating their importance for surgeons

For several decades, anatomists and biological anthropologists have made an intensive study in anatomical variations in ancestral and living humans. While many anatomical variants do not require clinical attention, some may present diagnostic problems or augur adverse symptoms. It is only in the last few decades that a plausible argument has been made that anatomical changes in human individuals and lineages demonstrate ongoing microevolution. Since the mid-19th century, there has been a reduction in differential mortality. Increased variation of heritable traits is a consequential outcome of relaxation of natural selection. Consequently, this has contributed to various anatomical variations in musculo-skeletal anatomy, vascular anatomy as well as congenital disorders such as spina bifida occulta. The authors argue that surgeons and anatomists should improve their knowledge of evolution and its continuing influence on human morphology. Simply repeating the old mantra that anatomical variations are important because knowledge of them minimizes surgical complications, albeit important, is inadequate.

Lymphatic Pump Manipulation in Patients with Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) show a persistent local and systemic inflammatory pattern which stimulates negative remodeling of the airways. Globally, chronic respiratory disease is the third leading cause of death. One of the rehabilitative strategies used to improve the symptoms of COPD patients is the use of lymphatic pump manipulation; this procedure aims to reduce the concentration of pro-inflammatory substances. However, research results relating to this technique are contradictory. This article reviews the mechanisms that determine lymphatic flow, lymphatic lung anatomy, and the lymphatic response to respiratory pathology. Also highlighted is the manual approach to the mediastinum which can be used to improve the lymphatic and inflammatory response in COPD. Finally, new manual strategies have been discussed with which lymphatic flow in patients with COPD can be improved.

Impact of lymph node management on resectable non-small cell lung cancer patients

BACKGROUND

A surgical lung resection with systematic mediastinal lymph node (LN) dissection is recommended by the National Comprehensive Cancer Network guideline. However, the effective number of dissected LNs, stations and positivity is still controversial. The aim of this study is to identify the impact of total numbers, LN stations and positivity of dissected LNs on tumor recurrence and overall death in resectable non-small cell lung cancer (NSCLC).

METHODS

This prognostic study used a retrospective data collection design. Adult patients with clinical resectable NSCLC who underwent pulmonary resection and mediastinal lymphadenectomy at Chiang Mai University between June 2000 and June 2012 were enrolled in this study. A multilevel mixed-effects parametric survival model was used to identify the effect of numbers, LN stations and positivity of dissected LNs to tumor recurrence and mortality.

RESULTS

The average number of dissected LNs was 22.7±12.8. Tumor recurrence was found in 51.3% and overall mortality was 43.3%. The number of dissected LNs was a prognostic factor for tumor recurrence [HR 0.98, 95% confidence interval (CI): 0.96-0.99]. There was a significant difference at the cut-pointed value of 11 dissected LNs for tumor recurrence (HR 2.22, 95% CI: 1.26-3.92). Dissection less than 11 nodes and less than 5 stations indicated a poor prognostic factor for tumor recurrence: for 3-4 stations (HR 3.01, 95% CI: 1.22-7.42) and for 1-2 stations (HR 1.96, 95% CI: 1.04-3.72). The positivity of dissected LNs was also a prognostic factor for tumor recurrence and overall mortality (HR 1.01, 95% CI: 1.01-1.02 and HR 1.01, 95% CI: 1.01-1.03, respectively).

CONCLUSIONS

Eleven or more LN dissection with at least 5 stations influenced recurrent-free survival. Systematic LN dissection (SLND) should be performed not only to identify the positivity of dissected LNs but also to determine an accurate tumor nodal stage. A larger cohort should be further conducted to support these findings.