Right middle lobe syndrome after upper lobectomy: Role of the bronchial angle

Abstract

Background: Right middle lobe syndrome is part of a spectrum of relatively rare but serious conditions that may occur following right upper lobectomy. We aimed to assess whether the preoperative middle lobe bronchial angle on CT predicted patients at risk of developing middle lobe syndrome.

Method: All patients who had a complete upper lobectomy over 4 years were retrospectively reviewed for clinical and imaging findings of middle lobe syndrome. Patients with previous lung surgery, preoperative chemo- or radiation therapy, or more extensive surgical resection were excluded. Patient demographics and symptoms, the surgical, pathologic and bronchoscopy reports, and pre- and post-operative chest imaging, to include 3D CT reconstructions and measurements of the middle lobe angles in a subset of patients, were retrospectively reviewed.

Result: One hundred and twenty-eight patients met inclusion criteria. Ten (8%) had middle lobe syndrome based on symptoms and imaging features. Eight had severe middle lobe consolidation. Two had postoperative onset of wheezing, with middle lobe bronchial abnormality on CT. The pre- and postoperative middle lobe bronchial angles of 14 patients without middle lobe syndrome were compared to 10 patients with middle lobe syndrome. The middle lobe bronchus was completely obliterated postoperatively and could not be determined in 1 patient. There was no significant difference between the pre- and postoperative angles in patients with or without middle lobe syndrome.

Conclusion: Middle lobe syndrome occurred in 8% of patients with right upper lobectomy. The preoperative middle lobe bronchial angle did not predict patients at risk for developing middle lobe syndrome.

Figure 1.

A and B, A 57-year-old man was asymptomatic after RULL. No bronchoscopy was performed. 2D oblique CTs were performed. A) Preoperatively and B) 3 months after RULL. The RML bronchial angle (angled blue line) decreased from 155° to 109°, with a moderately severe short segment narrowing (arrow) of the RML bronchus. RULL = right upper lobe lobectomy; RML = right middle lobe.

Figure 2.

A and B, A 61-year-old woman manifested with RML atelectasis on day 1 following RULL. Bronchoscopy performed 4 days later revealed copious RML secretions but no RML bronchial angulation. 2D oblique CTs were performed A) preoperatively and B) 9 months after RULL. The RML bronchial angle (angled blue line) was not significantly changed after RULL (133° vs. 132°) despite long segment multifocal narrowing and angulation of the RML and segmental bronchi (arrows), which resolved on chest CT 14 months after RULL. RML = right middle lobe; RULL = right upper lobe lobectomy.

Figure 3.

A and B, A 59-year-old woman manifested with RML atelectasis on day 1 following RULL. No bronchoscopy was performed. A) Preoperative 3D volume rendered CT and B) 2D oblique CTon day 3 after RULL. The RML bronchial angle (angled blue line) decreased from 143° to 118°. Complete occlusion of the segmental and RML (arrow) bronchi and near complete RML consolidation (asterisk) resolved on CT performed 4.5 months later. RML = right middle lobe; RULL = right upper lobe lobectomy.