Postlobectomy Chest Radiographic Changes: A Quantitative Analysis

The effect of lobar shifting following right upper lobectomy on postoperative pulmonary function

OBJECTIVES

Lobes occasionally displace after lobectomy, referred to as "lobar shifting". However, the benefits, especially in postoperative pulmonary function, remain controversial. This study aimed to measure the effect of lobar shifting on postoperative pulmonary function especially in the right upper lobe.

METHODS

This retrospective study includes 273 right upper lobectomy patients (lobectomy group) and 24 right upper segmentectomy patients (segmentectomy group) from 2012 to 2021. The lobectomy group was further subdivided based on their Synapse Vincent® image: with their postoperative middle lobe bronchus shifted toward the head (shift group: 176 cases) and without (non-shift group: 97 cases). Several factors were examined to determine the cause of lobar shifting. The rate of measured actual postoperative forced expiratory volume in 1 s (FEV1.0) to predicted postoperative FEV1.0 was analyzed and compared among the three groups.

RESULTS

Factors that correlated with lobar shifting included age (p < 0.001), a relatively small middle lobe volume (p = 0.03), no adhesions (p < 0.001), and good upper/middle and middle/lower lobulation (p = 0.04, p = 0.02). The rate of measured actual postoperative FEV1.0 to predicted postoperative FEV1 for the shift, non-shift, and segmentectomy groups were 112.5%, 107.9%, and 103.1% (shift vs non-shift: p = 0.04, shift vs segmentectomy: p = 0.02, non-shift vs segmentectomy: p = 0.19).

CONCLUSIONS

Lobar shifting after right upper lobectomy is influenced by morphological factors and may have a beneficial impact on postoperative pulmonary function.

Preservation vs. dissection of inferior pulmonary ligament for thoracoscopic upper lobectomy: a prospective randomized controlled trial

OBJECTIVES

The proper procedure for inferior pulmonary ligament (IPL) during upper lobectomy remains a topic of debate. To address this matter, we carried out a trial comparing the clinical outcomes of IPL preservation versus IPL dissection during thoracoscopic upper lobectomy (TUL).

METHODS

Patients undergoing thoracoscopic left/right upper lobectomy (TLUL/TRUL) were assigned to either the dissection group (Group D) or the preservation group (Group P). Our primary objective was to quantify and compare the alterations in postoperative residual bronchial angle and lung volume changes between the two groups. Our secondary objective encompassed the assessment of various other intraoperative and postoperative outcomes.

RESULTS

Following adherence to the inclusion and exclusion criteria, we enrolled 100 patients (41 left and 59 right) in Group P and 108 patients (41 left and 67 right) in Group D for the study. Our findings revealed that in TLUL, Group P was able to reduce the degree of postoperative residual bronchial angle change (P < 0.05). Conversely, the situation was distinct for TRUL. We found no notable disparity between the two groups (P > 0.05) with regard to alterations in lung volume or the occurrence of postoperative complications-except for the duration of postoperative hospital stay (P < 0.05).

CONCLUSIONS

Our study suggests IPL preservation especially for TLUL when compared to TRUL, which have important implications for the clinical management of patients undergoing upper lobectomy.

Effect of inferior pulmonary ligament division on residual lung volume and function after a right upper lobectomy

OBJECTIVES

The requirement to divide an inferior pulmonary ligament (IPL) during an upper lobectomy has not been standardized. We evaluated the influence of the division of an IPL after a lobectomy of the right upper lobe.

METHODS

We evaluated 52 patients with lung cancer who underwent a video-assisted thoracoscopic lobectomy of the right upper lobe at Asan Medical Center between January 2011 and April 2014. These cases were stratified by division of the IPL or not, i.e. a preservation group (group P, n = 21) and a division group (group D, n = 31). The angle between the bronchus intermedius and the right middle lobe bronchus and the lung volume were measured using computed tomography. The results of the pulmonary function tests and the prevalence of complications were also reviewed.

RESULTS

The prevalences of atelectasis (P = 0.538), dead space (P = 0.084) and pleural effusion (P = 0.538) were not statistically different. The postoperative volumetric change of the right middle lobe (group P, -27 ± 97 ml; group D, -29 ± 111 ml; P = 0.950) and of the right lower lobe (group P, 397 ± 293 ml; group D, 335 ± 294 ml; P = 0.459) did not show statistical differences. The change in the bronchial angle was not statistically different between the groups (group P, -26.3 ± 13.7°; group D, -26.7 ± 13.6°; P = 0.930). The patients in group D experienced a greater loss in forced vital capacity than those in group P (group P, -0.16 ± 0.26 l; group D, -0.42 ± 0.33 l; P = 0.007), but the loss in the forced expiratory volume in 1 s was not significant (P = 0.328).

CONCLUSIONS

An IPL division does not produce significant differences in lung volume, bronchial angle change or prevalence of complications other than loss of forced vital capacity.

Postoperative Imaging After Lobectomy: Predicting the Displacement and Change in Orientation of Nonresected Lung Nodules

OBJECTIVES

The objective of this study was to determine the effect of a lobectomy to the location and orientation of nonresected lung nodule and its corresponding airway.

METHODS

We reviewed preoperative and postoperative computed tomography of patients who underwent lobectomies and have a separate nonresected nodule in the ipsilateral lung. Displacement of the nonresected nodule and angulation of its corresponding segmental bronchus were measured.

RESULTS

Fifty nodules from 40 patients (30 females, 10 male; mean ± SD age, 67 ± 7 years) were assessed. Nodules are displaced clockwise after right upper, right middle, and left lower lobectomies and counterclockwise after right lower and left upper lobectomies. Displacement of the remaining nodules was greater in the craniocaudal plane, followed by anteroposterior and transverses planes (mean, 3.7, 2.5, and 1.9 cm, respectively).

CONCLUSIONS

Remaining ipsilateral nodules and their associated segmental airways are displaced in a predictable fashion after lobectomy. This may help in the assessment of follow-up imaging.

Normal postoperative appearances of lung cancer

The major lung resections are the pneumonectomies and lobectomies. The sublobar resections are segmentectomies and wedge resections. These are performed either through open surgery through a thoracotomy or by video-assisted mini-invasive surgery for lobectomies and sublobar resections. Understanding the procedures involved allows the normal postoperative appearances to be interpreted and these normal anatomical changes to be distinguished from potential postoperative complications. Surgery results in a more or less extensive physiological adaptation of the chest cavity depending on the lung volume, which has been resected. This adaptation evolves during the initial months postoperatively. Chest radiography and computed tomography can show narrowing of the intercostal spaces, a rise of the diaphragm and shift of the mediastinum on the side concerned following major resections.

Perioperative outcomes of upper lobectomy according to preservation or division of the inferior pulmonary ligament

BACKGROUND

The aim of this study was to investigate the relationship between inferior pulmonary ligament division and postoperative complications.

METHODS

Medical records of 72 non-small cell lung cancer (NSCLC) patients who underwent video-assisted thoracic surgery (VATS) upper lobectomy between March 2012 and November 2013 performed by a single thoracic surgeon at our center were reviewed retrospectively. Patients were categorized into two groups: the division group, who underwent division of the inferior pulmonary ligament, and the preservation group, who did not. The division group included 43 patients (27 right, 16 left), while the preservation group included 29 (11 right, 18 left). Postoperative outcomes such as the presence of pleural effusion, chest tube duration, and changes in the angle and diameter of remnant bronchus were compared; bronchial diameter and angle were measured on three-dimensional (3D) reconstruction chest CT images.

RESULTS

Chest tube duration, duration of chest tube drainage >200 mL, and the presence of pleural effusion on chest X-rays taken 1 month after surgery were not significantly different between the two groups (P=0.07, 0.33, and 1.00, respectively). There were also no significant differences between groups in the presence of apical dead space or in change in bronchial angle (P=0.22 and 0.74, respectively). In 3D reconstruction images, changes in the diameter of the right middle, right lower, and left lower lobar (LLL) bronchi were similar between groups (P=0.72, 0.12 and 0.29, respectively). Change in the angle between the right bronchus intermedius (RBI) and the right middle lobar (RML) bronchus and between the RBI and the right lower lobar (RLL) bronchus were significantly different between the division and preservation groups (P=0.02 and 0.05, respectively).

CONCLUSIONS

Inferior pulmonary ligament division had no clear benefits. Complications related to excessive dislocation of remnant bronchi might be associated with inferior pulmonary ligament division, but further research is needed to elucidate this relationship.

Postoperative complications after thoracic surgery for lung cancer

Lung cancer is the leading cause of cancer-related deaths in the United States. Several surgical techniques are currently used as part of the standard of care for early-stage lung cancer. Differentiating normal postoperative changes from complications is essential in the management of these patients. This article will review the various surgical approaches used, ranging from wedge resection to pneumonectomy, and will outline their expected postsurgical changes. Early and late postsurgical complications will be described, some of which are unique to the type of surgery performed. In addition, local tumor recurrence is a form of postoperative complication and must be distinguished from typical postoperative or postradiation change. Knowledge of both common and uncommon postoperative complications is crucial in the follow-up of lung cancer patients.

SUMMARY STATEMENT

Familiarity with the appearance of postoperative complications in lung cancer patients is vital to distinguish it from the normal postoperative or postradiation appearance in follow-up imaging.

The effect of postoperative change in bronchial angle on postoperative pulmonary function after upper lobectomy in lung cancer patients

OBJECTIVES

Upper lobectomy inevitably leads to an upward displacement of the remaining lower lobe. Such displacement may result in bronchial angulation, thereby narrowing the airway. We hypothesized that the degree of displacement of the bronchus is associated with the degree of exacerbation of postoperative pulmonary dysfunction. This study investigated whether bronchial angulation affects postoperative pulmonary function.

METHODS

Patients undergoing upper lobectomy for lung cancer were retrospectively evaluated. A check for the presence of dyspnoea, pulmonary function test, chest X-ray and chest computed tomography (CT) were performed at 3 and 12 months postoperatively in these patients. The angle formed by the main bronchus and the bronchus intermedius on the right side and that by the main bronchus and the lower lobar bronchus were measured using the coronal view of the chest CT. We analysed the relationship between the change in bronchial angle and pulmonary function.

RESULTS

Ninety-nine patients were enrolled in this study. Among these patients, 50 underwent left upper lobectomy (LUL) and 49 underwent right upper lobectomy (RUL). Nine patients who underwent LUL showed worsening symptoms, and among them, 8 presented an increase in the angle. However, among the 9 patients with worsening symptoms after RUL, only 4 presented an increase in the angle. Decreased forced expiratory volume in 1 s (FEV1) from 3 to 12 months after surgery was observed in 16 patients in the LUL group and 14 in the RUL group. Exacerbation of pulmonary dysfunction was associated with an increase in the bronchial angle (P = 0.04 for LUL and P = 0.02 for RUL). The degree of angle change was also associated with the extent of FEV1 reduction (P = 0.02 for LUL and P = 0.02 for RUL).

CONCLUSIONS

Although the change in the bronchial angle is a physiological condition, it can reduce postoperative pulmonary function. The measurement of the change in the angle using the coronal view of a chest CT is a useful screening tool for predicting the postoperative reduction in FEV1.