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.

Curvature of the left main bronchus caused by postural change from supine to left lateral position

This study was designed to examine deviation of the bronchus by postural change from supine to lateral position during spontaneous respiration. Fifteen healthy volunteers [13 men and 2 women, mean age: 34 years (range 26-42)] participated. Chest radiograms (anterior-posterior) were acquired in the order of supine, left lateral, and right lateral position. The bilateral bronchus angles and secondary carina angles were measured in the acquired images, and the angles were compared between the supine and lateral positions to evaluate deviation of the bronchus in the lateral position. The left secondary carina angle in the supine position was 61.3° ± 4.0° and it significantly increased to 65.5° ± 6.0° in the left lateral position (P = 0.001), but no significant difference was noted in the left bronchus angle between the supine and left lateral positions (P = 0.158). The curvature of left main bronchus, which we defined more than 5° increase in secondary carina angle, was observed in a half of the male participants during left lateral position. We should be aware of these anatomical changes due to the surgical posture as a possible cause for ventilation failure during one-lung ventilation.

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.