Analysis of anatomical variations of the lingular artery of the left upper lobe using 3D computed tomography angiography and bronchography

The advantages of preoperative 3D reconstruction over 2D-CT in thoracoscopic segmentectomy

Performing a pulmonary segmentectomy is a complex process, with precise localization of pulmonary nodules and recognition of intraoperative anatomical variations posing significant challenges. This study aims to assess the advantages of preoperative three-dimensional reconstruction (3D-RE) in thoracoscopic segmentectomy. The study, at Fujian Medical University Cancer Hospital, analyzed data from segmentectomy patients from January 2016 to February 2022. It compared 3D-RE and two-dimensional computed tomography (2D-CT) preoperative scans, focusing on perioperative complications within30 days to identify any differences. This investigation encompassed a total of 265 instances, with 148 belonging to the 3D-RE group and 117 aligned with the 2D-CT group. The 3D-RE group showed reduced intraoperative blood loss and shorter postoperative hospital stays (P < 0.001). They also had higher rates of lymph node sampling and combined subsegmentectomy and segmentectomy procedures (P < 0.01). Postoperative complications, particularly pneumonia and lung fistula, were lower in the 3D-RE group (P = 0.041). The rates of minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC) were significantly higher in the 3D-RE group, while adenocarcinoma in situ (AIS) and benign cases were less common (P = 0.006). Surgical duration, chest tube duration, chest drainage volume, surgery complexity, and pathological diagnoses showed no significant differences between the groups. Utilization of preoperative 3D-RE holds potential to minimize both intraoperative and postoperative complications, thereby enhancing the safety and feasibility of undertaking segmentectomy procedures.

The learning curve of a bronchus-first method in bi-port video-assisted thoracoscopic surgery for left upper lobe lung cancer

Video-assisted thoracic surgery (VATS) has been widely used in lung cancer treatment. However, VATS left upper lobectomy (LUL) is complex due to the intricate branching pattern of the left pulmonary artery (PA). Nevertheless, VATS right upper lobectomy can be simplified through a bronchus-first and simultaneous vessel stapling technique. In this study, the learning curve was obtained while ensuring favorable oncological outcomes using bronchus-first method for VATS LUL. First, retrospective data of 148 consecutive patients who underwent VATS LUL (bronchus-first method) for non-small cell lung cancer (NSCLC) from March 2018 to October 2020 were analyzed. The learning curve was then assessed via cumulative sum (CUSUM) analysis. Moreover, data at different stages of the learning curve, including operation time, blood loss, postoperative hospital stay, lymph node harvested, thoracotomy conversion, postoperative complications, endoscopic stapler consumptions, and 3 year overall survival, were recorded. The learning curve was best modeled as the equation: y = - 7.78 + 2.05x-2.23 × 10-2x2 + 6.43 × 10-5x3, with a good-to-fit test R2 = 0.97. The surgeon entered the proficient stage (59th case-148th case) after consecutive operations of 58 cases (learning stage, 1st case-58th case). Notably, more lymph nodes were harvested in the proficient stage than in the learning stage (17.69 ± 1.47 vs. 15.53 ± 1.43, P < 0.01). Compared with the learning stage, the proficient stage was associated with shorter operation time (114.28 ± 8.56 min vs. 126.81 ± 7.30 min, P < 0.01), fewer blood loss (44.22 ± 7.75 mL vs. 57.41 ± 22.98 mL, P < 0.01), shorter postoperative hospital stay (6.02 ± 0.99 d vs. 7.22 ± 1.34 d, P < 0.01), and fewer endoscopic stapler consumptions (5.89 ± 0.64 vs. 6.53 ± 0.50, P < 0.01). However, thoracotomy conversion (4/90 vs. 5/58, P = 0.32), postoperative complications (10/90 vs. 11/58, P = 0.23) and 3 year overall survival (62.2% vs. 50.8%, log-rank test, P = 0.11) showed no significant difference between the two stages. The surgeon with former single-direction VATS lobectomy experience can master bronchus-first VATS LUL after attending to 58 cases.

Aberrant mediastinal basal pulmonary artery encountered at anatomical lung resection: A case report and review of the literature

INTRODUCTION

Abnormal branching of the pulmonary artery is often encountered in anatomical lung resection, which can potentially result in accidental vessel injury with life-threatening bleeding or extra lung resection. The mediastinal basal pulmonary artery (Arteria Praebronchialis, AP) is a very rare but potentially critical variant.

PRESENTATION OF CASE

We present the case of a patient with lung cancer accompanied by the left basal segmental pulmonary artery, independent A8a+9, which was liable to be injured during lower lobectomy with poor interlobar fissure development. This variation was preoperatively recognized using three-dimensional contrast-enhanced computed tomography (3D-CECT) angiography, and vessel injury was avoided.

DISCUSSION AND LITERATURE REVIEW

3D-CECT angiography was effective in identifying this rare but potentially critical variation, and it is desirable to perform it routinely before anatomical lung resection. A review of 31 AP cases revealed that the branching pattern of AP was independent (15 patients, 48 %) and common trunk type (16 patients, 52 %), one half for each. Mediastinal branching of the lingular artery was more frequent among the reported AP cases (71 %) than in general reports.

CONCLUSION

When mediastinal branches of left pulmonary artery are encountered, the possibility that it is AP should be always taken into account.

Right middle pulmonary vein classification by 3D-CT reconstruction and its clinical significance

Background

A profound understanding of the type of right middle lobe (RML) vein return is crucial for thoracic surgeons to ensure safe anatomic lung resection. In this study, the type of venous return in the RML and its clinical significance were analyzed using the 3D computed tomography (3D-CT) reconstruction technique.

Methods

This retrospective study analyzed the patients who underwent anatomical lobectomy or anatomical lung segment resection with preoperative 3D-CT reconstruction at the Department of Thoracic Oncology Surgery, Fujian Cancer Hospital from January 2020 to October 2022. The exclusion criteria were as follows: (I) blurred CT images and inadequate IQQA 3D reconstruction for clear visualization of bronchial and vascular subsegmental branches; (II) patients with a previous history of right middle lobectomy; (III) incomplete medical records.

Results

This study included 608 eligible cases, 245 males (40.30%) and 363 females (59.70%), with an average age of 58.61 years. We identified four major types of RML venous return, including 407 cases (66.94%) of central vein type, 123 cases (20.23%) of isolated vein type, 11 cases (1.81%) of basal vein type, and 67 cases (11.02%) of combined vein type. Furthermore, the central venous type comprised four subtypes: 191 cases (27.3%) had one branch, 165 cases (27.14%) had two branches, 43 cases (7.07%) had three branches, and 8 cases (1.32%) had more than three branches. The combined venous type includes four subtypes: combination type A (n=37 cases, 6.09%), combination type B (n=7 cases, 1.15%), combination type C (n=21 cases, 3.45%), and combination type D (n=2 cases, 0.33%).

Conclusions

Based on 3D-CT reconstruction, numerous types of venous return in the RML were found, highlighting the significance of 3D-CT reconstruction for thoracic surgeons. It plays a crucial role in understanding the type of RML venous return prior to surgery, providing invaluable information to ensure surgical safety and success.

Arteria Praebronchialis (AP) Found on MDCT: An Updated Incidence and Branching Patterns

Preoperative detection of the arteria praebronchialis (AP), a rare variant mediastinal branch of the left pulmonary artery, can be crucial to a successful left-lung surgery; if the AP is overlooked and ligated during surgery, the blood supply to the remaining lobe may be compromised. The purpose of this study was to update the incidence and branching patterns of the AP. From 18 April 2012 to 31 December 2022, contrast-enhanced CT was screened by one radiologist for the presence of AP. Branching patterns of the AP were analyzed by three thoracic radiologists. The incidence of AP was updated to 0.068% (18/26,310) from the previously reported 0.03%; the incidence of AP for male and female patients was 0.110% and 0.017%, respectively. AP supplied only the LLL in 10 cases and both the lingular division of LUL and LLL in nine cases. Dual segmental supply by both the AP and the normal left descending pulmonary artery existed in 15 cases; exclusive segmental supply by either artery existed in four cases. The AP supplies either the LLL alone or both LLL and the lingular division of LUL, and its incidence is not negligible in the male population, necessitating routine surveillance prior to pulmonary resection.

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 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.

Application of three-dimensional computed tomography imaging and reconstructive techniques in lung surgery: A mini-review

Background

Pulmonary surgery is an innovative discipline with increasing demands for minimally invasive techniques in complicated anatomical resections, warranting adequate preoperative imaging of relevant surgical anatomy to ensure safe and radical resection of target lesions. Over the recent years, the emergence of imaging techniques enabling three-dimensional reconstruction has exerted promising influence on pulmonary surgery, facilitating optimal surgical planning and easier identification of the spatial relationship between bronchovascular structures in the individual patient and aiding the safe resection of target pulmonary lesions. The goal of this mini-review is to provide an overview of three-dimensional computed tomography imaging within pulmonary surgery.

Methods

The authors performed a targeted qualitative review of the literature to identify current trends and to provide better understanding of three-dimensional reconstruction within the boundaries of pulmonary surgery.

Results

Three-dimensional reconstructive techniques can be used for resectability assessment, identification of surgically relevant interindividual anatomic variance and may improve perioperative outcomes.

Discussion

Three-dimensional reconstruction using computed tomography imaging improves surgical planning and there is evidence that it results in shorter operative times, less intraoperative blood loss and lower rates of surgical conversion, as it can be applied both pre- and intraoperatively.

A cross-sectional study: analysis of anatomical variation in the right upper lung intersegmental vein V2a based on a 3D reconstruction technique

BACKGROUND

This study aimed to summarize and analyze the anatomical structures of the right upper lung intersegmental vein V2a based on 3-dimensional (3D) reconstruction technology.

METHODS

We collected the enhanced computed tomography (CT) scans of 157 patients with pulmonary diseases, and reconstructed the right upper lung tissue structure through interactive qualitative and quantitative analysis (IQQA). According to the reconstruction results, the V2a of the right upper pulmonary intersegmental vein was returned to different veins for classification, and the subtypes were further subdivided according to the different vascular routes and the location of the pulmonary segmental bronchus.

RESULTS

Among 157 patients, there were 4 types of V2a according to the anatomical position of the veins. In type B (15 cases, 9.6%), V2a returned to the apical vein V1. In type C (2 cases, 1.3%), V2a did not exist, while in type D (1 case, 0.6%), V2a directly flowed into the right atrium. Type A is further divided into three subtypes (A1, A2, A3) according to the type of veins returned and the anatomical location of their confluence. In subtype A1 (110/139 cases, 79.1%), V2a returned to the posterior segment central vein. In subtype A2 (8/139 cases, 5.8%), V2a flowed from the B2 mediastinal surface down to the interlobular part of the posterior segmental vein. In subtype A3 (21/139 cases, 15.1%), V2a flowed between B1a and B2a and back to the central vein at the junction of the B2 and B3 bronchus. Type B is further divided into 3 subtypes (B1, B2, B3) according to the location of the apical posterior segmental bronchus. In B1 subtype (1/15 cases, 6.7%), V2a continued from the mediastinal surface of B1 back down to V1. In B2 subtype (7/15 cases, 46.7%), V2a continued from the medial side of the B1 lung back down to V1. In subtype B3 (7/15 cases, 46.7%), V2a flowed back into the central part of the posterior segmental vein.

CONCLUSIONS

This study, supported by 3D reconstruction technology, preliminarily summarized the V2a typology and further refined the anatomical differences of each subtype.