CT of the bronchus intermedius: frequency and cause of a nodule in the posterior wall on normal scans

An analysis of the left top pulmonary vein and comparison with the right top pulmonary vein for lung resection by three-dimensional CT angiography and thin-section images

PURPOSE

The right top pulmonary vein (RTPV) is defined as an anomalous branch of the right superior PV (SPV) draining into the PV or left atrium (LA). Several previous reports have described the RTPV, but only a few have mentioned the left top PV (LTPV). The present study aimed to evaluate the branching patterns of the RTPV and LTPV using thin-section CT images and three-dimensional CT angiography (3D-CTA).

MATERIALS AND METHODS

This study included 1437 consecutive patients for evaluation of the right side and 1454 consecutive patients for the left side who were suspected of lung cancer and underwent CTA. We assessed the presence of each RTPV and LTPV and their branching patterns on the CTA images. When the RTPV or LTPV was identified, the maximum short-axis diameter was measured.

RESULTS

RTPV was found in 9.1% (131/1437), whereas LTPV was found in 2.9% (42/1454) of the patients. RTPV was also observed in 17.1% (7/41) of LTPV cases, except for one case in which the right side could not be evaluated. The most common RTPV inflow site was the right inferior PV (IPV) in 64.9% (85/131) of the patients, whereas that of the LTPV was the left IPV in 100.0% (42/42) of the patients. The mean diameter of the RTPV and LTPV was 3.3 mm (range, 1.3-7.5 mm) and 2.4 mm (range, 0.9-6.3 mm), respectively (P < 0.01).

CONCLUSION

The top PV branching pattern variations can be evaluated using thin-section CT and 3D-CTA images. RTPV is not a rare finding, and LTPV should also be identified in lung cancer cases scheduled for resection.

Anomalous segmental pulmonary vein: additional V6 behind the bronchus intermedius draining into the superior pulmonary vein

Anatomical variations of pulmonary venous drainage have been widely described in the literature in order to perform safe thoracic surgical procedures. We report a case of anomalous vein from the superior segment of the right lower lobe running in the posterior mediastinum and draining into the superior pulmonary vein. As the patient showed a usual right inferior pulmonary vein, formed by the union of the superior segment right lower lobe vein (V6) and the common basal vein joining the left atrium, the uncommon segmental pulmonary vein described was named: additional V6. It was identified preoperatively and recognized intraoperatively during thoracoscopic right lower lobectomy and lymph node dissection performed for lung cancer treatment. Diagnostic imaging and careful surgical dissection are helpful tools to avoid intraoperative bleeding and other complications during thoracic surgical procedures due to unrecognized vascular anomalies.

A right pulmonary vein abnormality treated with 3D CT assistance in thoracoscopic surgery for esophageal cancer: a case report

BACKGROUND

Anomalous bifurcation of the right superior pulmonary vein is an important anomaly that should be recognized not only in respiratory and cardiac surgeries, but also in esophageal surgery for the safe performance of surgery. We report a case in which thoracoscopic esophagectomy was safely performed using preoperative three-dimensional computed tomography (3D CT) imaging.

CASE PRESENTATION

An 81-year-old male patient received an upper gastrointestinal endoscopy, which revealed a 20-cm incisor at the entrance, 43-cm EGJ, and 30-mm large type 1 + IIc lesion between the 23-cm and 26-cm incisors; biopsy showed squamous cell carcinoma (SCC). Contrast-enhanced CT showed wall thickening in the anterior wall of the upper thoracic esophagus, without evidence of multi-organ invasion or lymph node metastasis. In addition, a break in the right pulmonary vein passing dorsal to the right main bronchus and flowing directly into the left atrium was observed, and 3D CT was performed preoperatively to confirm the 3D positioning. Positron emission tomography (PET)-CT showed a high degree of accumulation (SUVmax 19.95) in the upper thoracic esophagus. The patient was diagnosed with upper thoracic esophageal cancer, cT2N0M0 cStage II, and underwent thoracoscopic subtotal esophagectomy (three-region dissection) and gastric tube reconstruction. The dorsal inflow of the pulmonary vein in the right main bronchus, which was recognized on preoperative CT, was confirmed and preserved. The pathological diagnosis was basaloid squamous cell carcinoma, pT1b(SM1)N0(0/58)M0 pStage I. The postoperative course was uneventful, and the patient was discharged on postoperative day 20.

CONCLUSIONS

The anomalous bifurcation of the pulmonary vein in the right upper lobe area required attention because of its potential to cause massive bleeding and difficulty in securing the operative field if misidentified and damaged during surgery. Although it is not frequently encountered, it is the bifurcation anomaly that esophageal surgeons must bear in mind due to its severe consequences. Preoperative image-reading and intraoperative manipulation of this vessel are imperative for surgical safety.

[Single-phase Pulmonary Arteriovenous Separation CT Protocol with Estimated Time of Arrival Method Using 3rd Generation Dual Source CT: Its Success Rate of Pulmonary Arteriovenous Separation in Our Experience of 223 Cases]

We retrospectively investigated the success rate of pulmonary arteriovenous separation in a single-phase computed tomography (CT) protocol using the estimated time of arrival (ETA) method. A total of 223 patients who underwent a single-phase CT protocol using the ETA method for pulmonary arteriovenous separation were included in the analysis. Dual source CT (SOMATOM Force, SIEMENS) was used for imaging. The tube voltage was 80 kVp, and the scan mode was turbo flash spiral mode. CT values of main pulmonary artery (MPA), peripheral pulmonary artery (pPA), peripheral pulmonary vein (pPV), left atrium (LA), ascending aorta (AAo) and descending aorta (DAo) were measured. When the difference in CT values on the central side was 100 Hounsfield unit (HU) or more, it was judged that the separation was successful. The mean CT values were 671.9±154 HU for MPA, 424.4±81.2 HU for LA, 551.1±142.6 HU for pPA, 351.6±94.0 HU for pPV, 362.2±75.8 HU for AAo, and 282.7±83.7 HU for DAo. The mean difference in CT values of the pulmonary artery and vein was 247.5±138.9 HU on the central side and 199.5±133.0 HU on the peripheral side. There were 90.1% of cases where the difference in CT values on the central side was 100 HU or more. In addition, a strong positive correlation (r=0.849, p<0.001) was found between the CT value of MPA and the CT value difference on the central side. The success rate of pulmonary arteriovenous separation by the ETA method, which is a method that enables stable pulmonary arteriovenous separation, was 90.1%.

Classifying the destination of right top pulmonary vein in 31 clinical cases

Disruption in the flow of blood vessels is of great concern during thoracic surgery. Preoperative 3-dimensional computed tomography facilitates visualization of the exact location and course of blood vessels. The right posterior upper lobe segmental vein, known as the right top pulmonary vein (RTPV), is an anomalous vein beginning at the right upper lobe and running through the posterior surface of the intermediate bronchus. We clinically investigated 31 patients with RTPV who underwent lobectomy or total resection of the right lung in our hospital or related institutions. We classified the final destination of RTPV into four types. The RTPV flowed into the left atrium in 35.5% of cases, superior pulmonary vein in 9.7%, inferior pulmonary vein in 41.9%, and independently into V6 in 12.9%. An RTPV with a diameter ≥ 5 mm was considered a main drainage vein in S2. We should pay attention to the RTPV during right lung lobectomy.

Three-dimensional computed tomography image-oriented successful thoracoscopic subtotal esophagectomy for an esophageal cancer patient with an anomalous right superior pulmonary vein: A case report

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Case of esophageal cancer associated with an aberrant V2.

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Used preoperative 3D-CT for performing safe VATS-E.

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Preoperative contrast-enhanced 3D-CT clearly depicted the aberrant V2.

Background

Subcarinal lymphadenectomy is an essential procedure in curative esophagectomy for esophageal cancer. The right superior pulmonary vein (RSPV) and its branches are usually located in front of the right main or intermediate bronchus. However, an anomalous posterior branch (aberrant V2) of RSPV passes behind the right intermediate bronchus, where the aberrant V2 may be embedded in the subcarinal nodal packet. This can lead to unanticipated bleeding when dissecting the subcarinal lymph node. We present a case study on the use of preoperative three-dimensional contrast-enhanced computed tomography (3D-CT) for performing a safe video-assisted thoracoscopic surgery-esophagectomy in lower thoracic esophageal cancer.

Case presentation

A 77-year-old man had esophageal cancer associated with an aberrant V2 passing behind the right intermediate bronchus. Esophagogastroduodenoscopy revealed a type 1 tumor in the lower thoracic esophagus. Contrast-enhanced and 3D-CT scans showed a space-occupying lesion with contrast enhancement and an aberrant V2 passing behind the right intermediate bronchus, respectively. The patient was then diagnosed with lower thoracic esophageal cancer (cT2cN1cM0 cStage II). As per the patient’s request, he underwent a surgery-first approach followed by adjuvant chemotherapy. The patient underwent video-assisted thoracoscopic surgery-esophagectomy (VATS-E) with three-field lymphadenectomy, and a large aberrant V2 involving the subcarinal nodal packet was recognized behind the right intermediate bronchus. After the thoracoscopic subtotal esophagectomy with three-field lymph node dissection, laparoscopy-assisted reconstruction of the esophagus was performed with elevation of the gastric conduit to the neck. Recurrent laryngeal nerve palsy was not observed. He started to receive rehabilitation for swallowing on day 3 and resumed oral intake on day 10 after surgery. The final pathological diagnosis was squamous cell carcinoma of the esophagus (pT3N1M0 pStageIII).

Conclusions

Preoperative contrast-enhanced 3D-CT clearly depicted the aberrant V2, which enabled us to perform a safe VATS-E with three-field lymphadenectomy. Thorough understanding of the anatomical configuration of the pulmonary vessels and bronchus is important for avoiding unexpected bleeding during subcarinal lymphadenectomy. 3D-CT imaging study is useful for recognizing the anomalous RSPV before surgery.

Right top pulmonary veins associated with lung incomplete fissure and displaced bronchus: a retrospective study using multidetector computed tomography

OBJECTIVE

Anatomical features associated with the right top pulmonary vein (RTPV) remain unclear. This study aimed to reveal the incidence, form and associated pulmonary anatomical features of RTPVs.

METHODS

Thoracic computed tomography images taken from 4673 patients at our hospital between 2016 and 2018 were analyzed retrospectively for frequency, bifurcation pattern, inflow site, vascular diameter, and associated pulmonary anatomical features of RTPV.

RESULTS

RTPVs were observed in 154 (3.3%) patients; the mean diameter was 3.7 mm. The bifurcation patterns of without (V² type) and with branches of the right superior segmental vein (V²⁺⁶ type) were present in 50 and 104 patients, respectively. The inflow sites were the superior pulmonary vein (SPV group) and other sites (non-SPV group) in 86 and 68 patients, respectively. The incidence of incomplete fissure (ICF) in patients with and without RTPV was 44.2% and 7.9% (p < 0.001), respectively. The incidence of displaced bronchus (DB) with and without RTPV was 7.8% and 0.8% (p < 0.001), respectively. The mean diameter in the SPV and non-SPV groups were 4.0 mm and 3.3 mm, respectively (p = 0.002). The incidence of ICF in the group of V²⁺⁶ and V² types were 51.0% and 30.0%, respectively (p = 0.016). The incidence of ICF (54.4% vs 36.0%, p = 0.033) and DB (16.2% vs 1.1%, p < 0.001) increased significantly in the non-SPV group compared to the SPV group.

CONCLUSION

In patients with RTPV the incidence of ICF and DB increased. Moreover, the bifurcation patterns and inflow sites were associated with the anatomical features of the lung.

Accessory right V6 behind the bronchus intermedius during VATS right upper lobectomy

INTRODUCTION

The anatomical abnormalities in pulmonary veins can have a serious impact on pulmonary resections.

PRESENTATION OF CASE

We report the case of a 70-year-old woman undergoing VATS right upper lobectomy for the treatment of non-small cell lung cancer. During subcarinal dissection, an anomalous vein draining from the superior segment of the right lower lobe into the left atrium and passing behind the bronchus intermedius was incidentally discovered. The patient had, in addition to the inferior pulmonary vein formed by the confluence of superior and common basal veins, a supernumerary vessel identified as: accessory right V⁶. Retrospective review of preoperative enhanced chest computed tomography confirmed the pulmonary vascular anomaly.

DISCUSSION/CONCLUSION

A careful dissection during pulmonary resections can help to recognize variations of the pulmonary veins, avoiding unexpected intraoperative complications.

Comprehensive Cross-sectional Imaging of the Pulmonary Veins

The pulmonary veins carry oxygenated blood from the lungs to the heart, but their importance to the radiologist extends far beyond this seemingly straightforward function. The anatomy of the pulmonary veins is variable among patients, with several noteworthy variant and anomalous patterns, including supernumerary pulmonary veins, a common ostium, anomalous pulmonary venous return, and levoatriocardinal veins. Differences in pulmonary vein anatomy and the presence of variant or anomalous anatomy can be of critical importance, especially for preoperative planning of pulmonary and cardiac surgery. The enhancement or lack of enhancement of the pulmonary veins can be a clue to clinically important disease, and the relationship of masses to the pulmonary veins can herald cardiac invasion. The pulmonary veins are also an integral part of thoracic interventions, including lung transplantation, pneumonectomy, and radiofrequency ablation for atrial fibrillation. This fact creates a requirement for radiologists to have knowledge of the pre- and postoperative imaging appearances of the pulmonary veins. Many of these procedures are associated with important potential complications involving the pulmonary veins, for which diagnostic imaging plays a critical role. A thorough knowledge of the pulmonary veins and a proper radiologic approach to their evaluation is critical for the busy radiologist who must incorporate the pulmonary veins into a routine "search pattern" at computed tomography (CT) and magnetic resonance imaging. This article is a comprehensive CT-based imaging review of the pulmonary veins, including their embryology, anatomy (typical and anomalous), surgical implications, pulmonary vein thrombosis, pulmonary vein stenosis, pulmonary vein pseudostenosis, and the relationship of tumors to the pulmonary veins. Online supplemental material is available for this article. ^©RSNA, 2017.

Anomalous right upper lobe venous drainage

Lung resections are usually not associated with significant bleeding, but can be fatal, especially in cases of video-assisted thoracoscopic surgery (VATS). Anomalous vascular structures could be a major reason for unexpected bleeding in such surgeries. We present a case of an aberrant upper lobe pulmonary vein that was encountered posterior to the right upper lobe bronchus during a right upper lobectomy via thoracotomy. The anomalous pulmonary vein was identified preoperatively on a computed tomography (CT) scan and hence was looked for before dividing the bronchus. Many centres are adopting the VATS approach for performing lung resections. If an anomalous vein is present posterior to the bronchus, it might be in a blind spot and could be damaged inadvertently, leading to profuse and potentially fatal bleeding. We conclude that the identification of anomalous vascular structures prior to surgery with the help of CT helps in avoiding adverse outcomes.

Successful subcarinal dissection using a laparoscopic transhiatal approach for esophageal cancer with an anomalous pulmonary vein

We herein reported a case of a dangerous anomaly of a pulmonary vein in subcarinal dissection. A 74-year-old man underwent esophagectomy with systematic nodal dissection using a laparoscopic transhiatal approach. Under pneumomediastinum pressure, dissection of the posterior plane of the pericardium was extended, and a vessel that independently drained into the left atrium was identified. Although this anomalous vein penetrated the subcarinal lymph nodes and crossed behind the right main bronchi, subcarinal dissection was successfully performed without its injury. Our surgical procedure enabled the intraoperative identification of this rare abnormality, an aberrant segmental vein in the right upper lobe, and safe en bloc subcarinal dissection.

Journal Club: Comparison of assessment of preoperative pulmonary vasculature in patients with non-small cell lung cancer by non-contrast- and 4D contrast-enhanced 3-T MR angiography and contrast-enhanced 64-MDCT

OBJECTIVE

The purpose of this article is to prospectively and directly compare the capabilities of non-contrast-enhanced MR angiography (MRA), 4D contrast-enhanced MRA, and contrast-enhanced MDCT for assessing pulmonary vasculature in patients with non-small cell lung cancer (NSCLC) before surgical treatment.

SUBJECTS AND METHODS

A total of 77 consecutive patients (41 men and 36 women; mean age, 71 years) with pathologically proven and clinically assessed stage I NSCLC underwent thin-section contrast-enhanced MDCT, non-contrast-enhanced and contrast-enhanced MRA, and surgical treatment. The capability for anomaly assessment of the three methods was independently evaluated by two reviewers using a 5-point visual scoring system, and final assessment for each patient was made by consensus of the two readers. Interobserver agreement for pulmonary arterial and venous assessment was evaluated with the kappa statistic. Then, sensitivity, specificity, and accuracy for the detection of anomalies were directly compared among the three methods by use of the McNemar test.

RESULTS

Interobserver agreement for pulmonary artery and vein assessment was substantial or almost perfect (κ=0.72-0.86). For pulmonary arterial and venous variation assessment, there were no significant differences in sensitivity, specificity, and accuracy among non-contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 50%; specificity, 98.5%; accuracy, 93.2%), 4D contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 62.5%; specificity, 100.0%; accuracy, 95.9%), and thin-section contrast-enhanced MDCT (pulmonary arteries: sensitivity, 91.4%; specificity, 89.5%; accuracy, 90.4%; pulmonary veins: sensitivity, 50%; specificity, 100.0%; accuracy, 95.9%) (p>0.05).

CONCLUSION

Pulmonary vascular assessment of patients with NSCLC before surgical resection by non-contrast-enhanced MRA can be considered equivalent to that by 4D contrast-enhanced MRA and contrast-enhanced MDCT.

Evaluation of effects of bronchiectasis on bronchial artery diameter with multidetector computed tomography

BACKGROUND

Among patients with increased bronchial artery diameter there is a significant association between hemoptysis and bronchiectasis score. The higher score of bronchiectasis, the higher risk of hemoptysis development.

PURPOSE

To investigate the association of stages of bronchiectasis based on a computed tomography (CT) grading system, with bronchial artery diameter and hemoptysis in patients with bronchiectasis.

MATERIAL AND METHODS

Patients with lung pathologies other than bronchiectasis, which may cause hemoptysis, were excluded from the study. One hundred and forty-five patients who underwent contrast-enhanced thorax CT by a 64-detector CT for various indications, and who were diagnosed with bronchiectasis, were evaluated retrospectively. CT examinations were carried out by two radiologists with 9 and 4 years of experience with chest radiology, respectively. The diameters of the right and left bronchial arteries were measured 1 cm from the aortic origin and perpendicular to the vessel axis. Cases were assessed based on the Bhalla CT scoring system. The hemoptysis history of every patient was taken.

RESULTS

The diameters of the right and left bronchial arteries were significantly greater in patients with scores of 2 and 3 bronchiectasis than in patients with a score of 1. This was significantly greater in patients with a score of 3 than in patients with a score of 2 (P < 0.05). In patients with a score of 1, the right bronchial artery diameter was significantly greater than that of the left bronchial artery (P < 0.05). Right bronchial artery diameters were significantly greater than left bronchial artery diameters in score 3 patients (P < 0.05). A significant association was observed between hemoptysis and bronchiectasis in patients with increased bronchial artery diameter (P < 0.05).

CONCLUSION

In patients with bronchiectasis, as the stage of bronchiectasis increases, the bronchial artery diameters and the risk of hemoptysis increase. We think that in patients who are diagnosed with bronchiectasis via multidetector CT (MDCT), based on scoring with bronchial artery diameters, the risk of hemoptysis can be estimated, and early management plans can be implemented.

An anomalous segmental vein of the left upper lobe of the lung: preoperative identification by three-dimensional computed tomography pulmonary angiography

A number of variations in the pulmonary arteries and veins have been documented, and the information is very important for performing a safe lung resection. This report describes a case of an anomalous segmental vein of the left upper lobe of the lung. The patient was a 75-year old male who was suspected to have lung cancer in the left upper lobe. A contrast-enhanced computed tomography showed a vessel behind the left lower bronchus. A three-dimensional computed tomography angiography demonstrated that it was an anomalous vein for the apicoposterior segment of the left upper lobe of the lung, draining into the left inferior pulmonary vein. The aberrant vein was readily identified during surgery and was divided without injury, and a left upper lobectomy was successfully performed. Aberrant pulmonary veins for the superior segment of the right upper lobe of the lung are rarely observed, and the same kind of anomaly on the left side has not been reported.

A dangerous venous variation in thoracoscopic right lower lobectomy

Anatomical variations of the pulmonary vessels present a potential risk of intraoperative bleeding and damage to pulmonary circulation during pulmonary resection. We present details of a dangerous variation of the superior pulmonary vein associated with thoracoscopic right lower lobectomy that could potentially be divided if there was no preoperative foreknowledge of individual vessel configurations.

Right top pulmonary vein: Evaluation with 64 section multidetector computed tomography

PURPOSE

To evaluate the incidence and anatomic features of the rare variant of the pulmonary veins named "right top pulmonary vein" as depicted with 64 section multidetector computed tomography (MDCT).

MATERIALS AND METHODS

MDCT of 610 patients obtained over 12 months period for diagnosis of suspected thoracic or cardiac pathology were routinely reviewed in transverse and 3D images. The frequency of right top pulmonary vein (RTPV) was determined and anatomic features were also documented.

RESULTS

Right top pulmonary vein (RTPV) is a supernumerary vein arising from the roof of the right part of the left atrium separately from the orifice of the right superior pulmonary vein. It crosses behind the intermediate bronchus and drains mainly posterior segment of the right upper lobe but also receives few subsegmental branches of superior segment of the right lower lobe. It was detected in 2.2% of patients (14/610). The mean diameter of RTPV was 5.1 mm.

CONCLUSION

The RTPV is a rare venous drainage variation of pulmonary veins. It is important to be aware of this anatomic pattern for avoiding misinterpretation of pulmonary venographic findings, inadvertent ablation of pulmonary vein and perioperative bleeding during video assisted thorocoscopic lobectomy.

Right Upper Lobe Venous Drainage Posterior to the Bronchus Intermedius: Preoperative Identification by Computed Tomography

BACKGROUND

Anatomical variations of the pulmonary vessels relevant to pulmonary surgery are of concern to thoracic surgeons. Among such variations, the right upper lobe vein posterior to the bronchus intermedius (UVPBI) has received little attention thus far.

METHODS

Chest computed tomographic images and medical records of 725 patients were retrospectively reviewed. The frequency, drainage pattern, diameter, and associated anatomical characteristics of the UVPBI were assessed, and our right thoracotomy cases with the UVPBI were examined.

RESULTS

The UVPBI was found in 41 (5.7%) of 725 computed tomography cases, and in 9 (3.9%) of 230 right thoracotomy cases. Three UVPBI drainage sites were observed: (1) the superior pulmonary vein group, 55%; (2) the inferior pulmonary vein group, 41%; and (3) the superior segmental vein group, 4%. The diameter of the UVPBI at the level of the bronchus intermedius ranged from 1 to 7 mm (4.1 +/- 1.6 mm). The diameter of the UVPBI in the superior pulmonary vein group was significantly greater than that in the inferior pulmonary vein group (p < 0.01). The prevalence of a central vein was 43.9% for all UVPBI cases and 15.8% for large UVPBI cases (> or = 5 mm in diameter). Of the 9 right thoracotomy patients, 1 suffered UVPBI injury; this patient's UVPBI was not identified either preoperatively or intraoperatively.

CONCLUSIONS

The UVPBI is not as rare as was previously believed. It can be a main drainage route of the right upper lobe. Preoperative identification of this venous variation by computed tomography is useful for safe and accurate surgical procedures.