Analysis of bronchial and vascular patterns in left upper lobes to explore the genesis of mediastinal lingular artery and its influence on pulmonary anatomical variation

Evolution of Three-Dimensional Computed Tomography Imaging in Thoracic Surgery

Radiologic reconstruction technology allows the wide use of three-dimensional (3D) computed tomography (CT) images in thoracic surgery. A minimally invasive surgery has become one of the standard therapies in thoracic surgery, and therefore, the need for preoperative and intraoperative simulations has increased. Three-dimensional CT images have been extensively used, and various types of software have been developed to reconstruct 3D-CT images for surgical simulation worldwide. Several software types have been commercialized and widely used by not only radiologists and technicians, but also thoracic surgeons. Three-dimensional CT images are helpful surgical guides; however, in almost all cases, they provide only static images, different from the intraoperative views. Lungs are soft and variable organs that can easily change shape by intraoperative inflation/deflation and surgical procedures. To address this issue, we have developed a novel software called the Resection Process Map (RPM), which creates variable virtual 3D images. Herein, we introduce the RPM and its development by tracking the history of 3D CT imaging in thoracic surgery. The RPM could help develop a real-time and accurate surgical navigation system for thoracic surgery.

Clinically important pulmonary vascular variations: a narrative review

Background and Objective

Pulmonary vascular variations are a major factor in thoracic surgeries. Minimally invasive techniques, such as video-assisted thoracic surgery (VATS) used in non-small lung cancer treatment, have a limited field of view and no haptic feedback. Additionally, new studies suggest that segmentectomies are beneficial for patients. Accurate knowledge of vascular patterns and variants is crucial for conducting such procedures safely. The aim of this review was to systematize data in a useful manner from studies and case reports concerning pulmonary vascular variations and patterns.

Methods

We conducted a search on the PubMed and Embase databases. We used classifications of Nagashima, Yamashita, Boyden, Maciejewski, and Shimizu.

Key Content and Findings

The analysis showed that more data on the incidence rate and vascular patterns of certain bronchopulmonary segments are needed. Venous variations are a major factor in segmental resections, but additional data regarding incidence and pattern types are needed. Surgeons need to be aware of vascular variations as they can influence procedures in seemingly unrelated areas. The majority of studies emphasize the use of three-dimensional (3D) reconstruction of computed tomography (CT) for accurate planning of any thoracic procedures.

Conclusions

Abnormal vessels pose a risk in various procedures performed within the thorax, and the data in this review could be valuable in different medical areas in this regard.

Pulmonary Arterial Anatomical Patterns: a Classification Scheme Based on Lobectomy and 3D-CTBA

PURPOSE

 Preoperative evaluation of pulmonary vascular and tracheal routes and variations is of great importance to the surgeon. Three-dimensional computed tomography bronchography and angiography (3D-CTBA) has evolved in recent years with the optimization of 3D reconstruction techniques and artificial intelligence. We aim to apply CT angiography and Exoview 3D reconstruction technology to assess patients' pulmonary arterial tree and its anatomical variants and to try to summarize a set of anatomical typing of the pulmonary arterial tree that is relatively easy and conducive to promoting teaching based on surgical habits of lobectomy.

METHODS

 A total of 358 patients hospitalized in the Department of Thoracic Surgery of the First Affiliated Hospital of Soochow University between July 2020 and August 2021 were included in this study. We carefully analyzed the site of emanation, alignment, and number of branches of the pulmonary artery according to a uniform classification method in conjunction with the two-dimensional CT images and transformed them into 3D reconstruction models.

RESULTS

 Different types of pulmonary artery were observed in 358 cases. We evaluated the complete pulmonary artery tree and counted the number and frequency of major arteries of the pulmonary based on the surgical habits of anatomical lobectomy.

CONCLUSION

 The 3D-CTBA technique enables us to adequately assess the anatomy of the pulmonary arteries. Moreover, we provide a practical classification scheme of pulmonary arterial anatomical patterns based on lobectomy and 3D-CTBA. Our data can be used by clinicians in the teaching of pulmonary artery anatomy and the preoperative preparation for anatomical lobectomy.

Comparison of early patient-reported outcomes between uniportal thoracoscopic segmentectomy and wedge resection for peripheral small-sized non-small-cell lung cancer

BACKGROUND

Analysis of patient-reported outcomes (PROs) offers valuable insights into distinguishing the effects of closely related medical procedures from the patient's perspective. In this study we compared symptom burden in patients undergoing uniportal thoracoscopic segmentectomy and wedge resection for peripheral small-sized non-small cell lung cancer (NSCLC).

METHODS

This study included patients with peripheral NSCLC from an ongoing longitudinal prospective cohort study (CN-PRO-Lung 3) who underwent segmentectomy or wedge resection with tumor diameter ≤ 2 cm and consolidation tumor ratio (CTR) ≤ 0.5. PROs data were collected using the Perioperative Symptom Assessment for Lung Surgery questionnaire pre-operatively, daily post-surgery up to the fourth hospitalization day, and weekly post-discharge up to the fourth week. Propensity score matching and a generalized estimation equation model were employed to compare symptom severity. In addition, short-term clinical outcomes were compared.

RESULTS

In total, data of 286 patients (82.4%) undergoing segmentectomy and 61 patients (17.6%) undergoing wedge resection were extracted from the cohort. No statistically significant differences were found in the proportion of moderate-to-severe symptoms and mean scores for pain, cough, shortness of breath, disturbed sleep, fatigue, drowsiness, and distress during the 4-day postoperative hospitalization or the 4-week post-discharge period before or after matching (all p > 0.05). Compared with segmentectomy, wedge resection showed better short-term clinical outcomes, including shorter operative time (p = 0.001), less intraoperative bleeding (p = 0.046), and lower total hospital costs (p = 0.002).

CONCLUSIONS

The study findings indicate that uniportal thoracoscopic segmentectomy and wedge resection exert similar early postoperative symptom burden in patients with peripheral NSCLC (tumor diameter ≤ 2 cm and CTR ≤ 0.5).

CLINICAL TRIAL REGISTRATION

Not applicable.

Segmentectomy-oriented anatomical model for enhanced precision surgery of the left upper lobe

Objective

To optimize surgical outcomes and minimize complications in complex segmentectomy of the left upper lobe, we investigated the topographical anatomy of the left upper lobe and developed a segmentectomy-oriented anatomical model.

Methods

A state-of-the-art 3-dimensional computed tomography workstation was used to visualize the intersegmental planes and associated veins to categorize the anatomical patterns influencing surgical procedures during left upper lobe segmentectomy. This included the central vein affecting S1+2 (apicoposterior segment) segmentectomy, the transverse S3 (anterior segment) affecting S3 segmentectomy, and other venous branching patterns in 395 patients who underwent thoracic surgery at our institution.

Results

The central vein was observed in 32% of the patients, necessitating access from the interlobar area after segmental artery and bronchus division. Transverse S3 incidence was 27%, revealing that only one-third of the patients required complete left upper lobe transection between S4 and S3 during S3 segmentectomy. A significant negative correlation was observed between the presence of transverse S3 and the central vein (<10% of patients with the central vein had transverse S3 and vice versa). In 6% of patients, the lingular segmental veins partially or entirely drained into the inferior pulmonary vein, potentially causing excessive or insufficient resection during surgery.

Conclusions

This study offers valuable insights into the topographic anatomy of the left upper lobe and presents a segmentectomy-oriented anatomical model for complex segmentectomies. Our approach enables a more precise and individualized surgical planning for patients undergoing segmentectomy based on their unique anatomy, which could thereby lead to improved patient outcomes.

Technical Considerations for Performing Safe and Effective Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a late complication of acute pulmonary thromboembolism owing to incomplete clot dissolution in pulmonary artery. Pulmonary endarterectomy is the first-line treatment for CTEPH. However, 40% of patients are not candidates for surgery because of distal lesions or age. Balloon pulmonary angioplasty (BPA), a catheter-based intervention, is increasingly being used worldwide for treating inoperable CTEPH. Previous BPA strategy had a major concern of reperfusion pulmonary edema as a complication. However, recent refined strategies promise safe and effective BPA. Five-year survival rate after BPA is 90% for inoperable CTEPH, comparable with that of operable CTEPH.

Anatomy of the lung revisited by 3D-CT imaging

The anatomy of the lung was originally described based on data acquired from cadaveric studies and surgical findings. Over time, computed tomography (CT) and three-dimensional (3D) imaging techniques have been developed, allowing for reconstruction and understanding of lung anatomy in a more intuitive way. The wide adoption of 3D-CT imaging technology has led to a variety of anatomical studies performed not only by anatomists but also by surgeons and radiologists. Such studies have led to new or modified classification systems, shed light on lung anatomy from a useful surgical viewpoint, and enabled us to analyze lung anatomy with a focus on particular anatomical features. 3D images also allow for enhanced pre- and intra-operative simulation, improved surgical safety, enhanced educational utility, and the capacity to perform large-scale anatomical studies in shorter time frames. We will review here the key features of 3D-CT imaging of the lung, along with representative anatomical studies regarding (I) general lung anatomy, (II) anatomy of the right and left lobes, and (III) features of interlobar vessels. The current surge of 3D imaging analysis shows that the field is growing, with the technology continuing to improve. Future studies using these new and innovative methodologies will continue to refine our understanding of lung anatomy while enhancing our ability to perform safe and effective surgical resections.

Analysis of bronchovascular patterns in the left superior division segment to explore the relationship between the descending bronchus and the artery crossing intersegmental planes

Background

A comprehensive understanding of the anatomical variations in the pulmonary bronchi and arteries is particularly essential to the implementation of safe and precise left superior division segment (LSDS) segmentectomy. However, no report shows the relationship between the descending bronchus and the artery crossing intersegmental planes. Thus, the purpose of the present study was to analyze the branching pattern of the pulmonary artery and bronchus in LSDS using three-dimensional computed tomography bronchography and angiography (3D-CTBA) and to explore the associated pulmonary anatomical features of the artery crossing intersegmental planes.

Materials and methods

The 3D-CTBA images of 540 cases were retrospectively analyzed. We reviewed the anatomical variations of the LSDS bronchus and artery and assorted them according to different classifications.

Results

Among all 540 cases of 3D-CTBA, there were 16 cases (44.4%) with lateral subsegmental artery crossing intersegmental planes (AX³a), 20 cases (55.6%) Without AX³a in the descending B³a or B³ type, and 53 cases (10.5%) with AX³a, 451 cases (89.5%) Without AX³a in the Without the descending B³a or B³ type. This illustrated that the AX³a was more common in the descending B³a or B³ type (P < 0.005). Similarly, there were 69 cases (36.1%) with horizontal subsegmental artery crossing intersegmental planes (AX^{1 + 2}c), 122 cases (63.9%) Without AX^{1 + 2}c in the descending B^{1 + 2}c type, and 33 cases (9.5%) with AX^{1 + 2}c, 316 cases (90.5%) Without AX^{1 + 2}c in the Without the descending B^{1 + 2}c type. Combinations of the branching patterns of the AX^{1 + 2}c and the descending B^{1 + 2}c type were significantly dependent (p < 0.005). The combinations of the branching patterns of the AX^{1 + 2}c and the descending B^{1 + 2}c type were frequently observed.

Conclusions

This is the first report to explore the relationship between the descending bronchus and the artery crossing intersegmental planes. In patients with the descending B³a or B³ type, the incidence of the AX³a was increased. Similarly, the incidence of the AX^{1 + 2}c was increased in patients with the descending B^{1 + 2}c type. These findings should be carefully identified when performing an accurate LSDS segmentectomy.

Analysis of pulmonary artery variation based on 3D reconstruction of CT angiography

Objective: The aim of this study is to acquire pulmonary CT (Computed tomography) angiographic data for the purpose of creating a three-dimensional reconstruction. Additionally, we aim to analyze the features and deviations of the branches in both pulmonary lobes. This information is intended to serve as a more comprehensive and detailed reference for medical professionals when conducting preoperative evaluations and devising surgical plans. Method: Between August 2019 and December 2021, 420 patients were selected from the thoracic surgery department at the First Hospital of Jilin University, and underwent pulmonary 64 channel contrast enhanced CT examinations (Philips ICT 256). The images were acquired at a 1.5 mm slice thickness, and the DCM files that complied with DICOM (Digital Imaging and Communications in Medicine) standards were analysed for 3D (three dimensional) reconstruction using Mimics 22.0 software. The reconstructed pulmonary artery models were assessed by attending chest surgeons and radiologists with over 10 years of clinical experience. The two-dimensional image planes, as well as the coronary and sagittal planes, were utilized to evaluate the arteries. The study analyzed the characteristics and variations of the branches and courses of pulmonary arteries in each lobe of the lungs, with the exception of the subsegmental arterial system. Two chest surgeons and two radiologists with professional titles-all of whom had over a decade of clinical experience-jointly evaluated the 3D models of the pulmonary artery and similarly assessed the characteristics and variations of the branches and courses in each lobe of the lungs. Results: Significant variations were observed in the left superior pulmonary artery across the 420 subjects studied. In the left upper lobe, the blood supply of 4 arteries accounted for 50.5% (n = 212), while the blood supply of 2 arteries in the left lower lobe was the most common, accounting for 79.5% (n = 334). The greatest variation in the right pulmonary artery was observed in the branch supply of the right upper lobe mediastinal artery. In the majority of cases (77.9%), there were two arteries present, which was the most common configuration observed accounting for 64% (n = 269). In the right inferior lobe of the lung, there were typically 2-4 arteries, with 2 arteries being the most common configuration (observed in 79% of cases, n = 332). Conclusion: The three-dimensional reconstruction of pulmonary artery CT angiography enables clear observation of the branches and distribution of the pulmonary artery while also highlighting any variations. This technique holds significant clinical value for preoperative assessments regarding lesions and blood vessels.

Analysis of variations in the bronchovascular pattern of the lingular segment to explore the correlations between the lingular segment artery and left superior division veins

Background

With the development of anatomical segmentectomy, the thoracic surgeons must master the anatomical variations of the pulmonary bronchi and vessels. However, there are only a few reports showing anatomic variations of the lingular segment (LS) using three-dimensional computed tomography bronchography and angiography (3D-CTBA). Thus, the present study aimed to analyze the bronchovascular patterns of the LS and explore the correlation between the lingular segment artery (LSA) and left superior division veins (LSDV).

Materials and methods

The 3D-CTBA data of the left upper lobe (LUL) were collected from patients who had undergone lobectomy or segmentectomy at Hebei General Hospital between October 2020 and October 2022. We reviewed the clinical characteristics and variations in bronchi and pulmonary vessels and grouped them according to different classifications.

Results

Among all 540 cases of 3D-CTBA, the branching patterns of LSA included 369 (68.3%) cases with the interlobar origin, 126 (23.3%) cases with the interlobar and mediastinal origin, and 45 (8.3%) cases with the mediastinal origin. The branching pattern of LSDV could be classified into three forms: Semi-central vein type (345/540, 63.9%), Non-central vein type (76/540, 14.1%), and Central vein type (119/540, 22.0%). There were 51 cases (9.4%) with Non-central vein type, 50 cases (9.3%) with Central vein type, 268 cases (49.6%) with Semi-central vein type in the interlobar type, and 7 cases (1.3%) with Non-central vein type, 9 cases (1.7%) with Central vein type, 29 cases (5.4%) with Semi-central vein type in the mediastinal type. Moreover, the Non-central vein type, the Central vein type, and the Semi-central vein type accounted for 18 (3.3%), 60 (11.1%), and 48 (8.9%) in the interlobar and mediastinal type. Combinations of the branching patterns of the LSA and LSDV were significantly dependent (p < 0.005). The combinations of the interlobar and mediastinal type with the Central vein type, and the interlobar type and the mediastinal type with the Semi-central vein type were frequently observed.

Conclusions

This study found the relationship between the LSA and LSDV and clarified the bifurcation patterns of the bronchovascular in the LS. Our data can be used by thoracic surgeons to perform safe and precise LS segmentectomy.

Anatomical variation analysis of left upper pulmonary blood vessels and bronchi based on three-dimensional reconstruction of chest CT

BACKGROUND

With its growing popularity and potential outcome, preoperative three-dimensional reconstruction of chest computed tomography (CT) has been widely used in video-assisted thoracic surgery (VATS) segmentectomy for treating non-small cell lung cancer (NSCLC). This study aimed to summarize the experience of anatomical variation analysis of left upper pulmonary blood vessels and bronchi based on the three-dimensional reconstruction of chest CT.

MATERIALS AND METHODS

A total of 103 patients with early-stage NSCLC were chosen to undergo VATS segmentectomy based on preoperative three-dimensional reconstruction of chest CT in our institute from September 2019 to July 2022. Data such as clinical characteristics and variations in blood vessels and bronchi were reviewed in this study.

RESULTS

The branches of the left lingular pulmonary artery may mutate into the LS1 + 2 + 3. A1 + 2 has four subtypes. The distribution of variation is relatively balanced, and the most common variation is type I (35/103, 33.9%). Most lingular arteries originate from the oblique cleft side of the lingular bronchus (79/103,76.7%). Most V(1 + 2)c* are small developments (70/103, 68.0%). The venous return of the proper segment mainly depends on V(1 + 2)b + c. The variation in the left upper lobe bronchus is complex. The most common variant is the bifurcation type (type A to G, 92/103, 89.3%) and bifurcation type A (62/103, 60.2%). The posterior apical segment artery of the left upper lobe is not accompanied by its bronchus.

CONCLUSIONS

The variation types of blood vessels and bronchus in the upper lobe of the left lung are complex. Preoperative CT-based three-dimensional reconstruction of pulmonary arteries, veins, and bronchi is of great significance. It can help understand the variations, accurately locate lesions before the surgery, and effectively plan surgeries.

The intersegmental pulmonary vein is not always located on the intersegmental plane of the lung: Evaluation with 3-dimensional volume-rendering image reconstruction

Objective

To clarify whether intersegmental pulmonary veins are always located on the intersegmental plane and determine the division from which blood flows into them.

Methods

We analyzed representative intersegmental veins located between the upper/lingular and superior/basal division of the lungs using preoperative chest computed tomography (CT) DICOM data from 22 patients who underwent lobectomy or segmentectomy during 2020. The location and blood flow of V³a+b and V⁶b+c were assessed using REVORAS (Ziosoft), a novel volume-rendering 3-dimensional (3D) image reconstruction software dedicated to lung segmentectomy.

Results

The V³a+b was in the upper division and on the intersegmental plane between the upper and lingular divisions of the left lung in 11 patients (50%) each. A main root of V³a+b was not found in the lingular division, but some peripheral flow in the V³a+b was derived from it in 14 patients (64%). The V⁶b+c was found in the superior division of the right lower lobe in 13 patients (59%) and the left lower lobe in 10 patients (45%), and on the intersegmental plane between the superior and basal division of the right lower lobe in 6 patients (27%) and the left lower lobe in 10 patients (45%). A main root of V⁶b+c was imperceptible in the basal division. Some peripheral blood flow was derived from the basal division in 6 patients (27%) with V⁶b+c veins located in the right lower lobe and in 8 patients (36%) with V⁶b+c veins located in the left lower lobe.

Conclusions

Precise evaluation of intersegmental veins using preoperative volume-rendering 3D reconstructed CT images provides useful anatomic information for separating intersegmental pulmonary parenchyma.