Tarek Mohsen MD, FRCS Cardiothoracic SurgeonCairo University Hospitals
The term “middle lobe syndrome” was first introduced by Graham and colleagues in 1948 for isolated middle lobe atelectasis caused by lymph node compression. Othercauses of a shrunken middle lobe without lymph node compression was pointed out later by Rubin and Rubin in 1950 for other causes including benign and malignant tumors or bronchiectasis.
The clinical presentation of (MLS) differs among age groups. In children it is a cause for persistent or intermittent wheezing in atopic and non atopic children making early recognition difficult and a lag between diagnosis and treatment is the rule. In adults specific clinical presentations like fever, cough, purulent sputum and hemoptysis usually point to early recognition for the clinical syndrome
Inthis study we retrospectively analyzed the etiology, indications and results of surgical intervention in the past six years for patients with MLS in different age groups.
A retrospective review of 84 consecutive patients with different age groups presented with MLS and, Cairo University Hospitals between Feb. 2004 and Dec. 2010 was undertaken. Our patients were divided according to their age group into pediatric group < 15 years old (39 patients) and adult group > 15 years old (45 patients). Both groups followed the same protocol of medical management prior to referral for surgical management.
At the chest department all patients underwent detailed history taking, thorough medical examination and an initial chest radiograph in both postero-anterior and lateral views showing middle lobe collapse / consolidation and or bronchiectasis. The initial management was conservative in the form of broad spectrum antibiotics, physiotherapy, mucolytics, inhaled bronchodilators, and inhaled corticosteroids. Re-evaluation after 4 – 6 weeks was done and in the event of persistent or recurrent of symptoms and lack of radiographic amelioration, these patients were subjected (HRCT) and bronchoscopic evaluation including bronchial lavage (BAL). Patients who were thought to be a high risk for malignancy e.g. age, smoking were placed on a faster track with initial HRCT and bronchoscopic biopsy.
Referralfor surgical management was based on failed conservative treatment, chronicity of the disease, bronchiectasis, hemoptysis, destroyed lobe, and malignancy.
Fibro-opticbronchoscopic evaluation was done in all patients in the adult group to explore the tracheobroncheal tree. BAL was sent for quantitative culture and sensitivity for aerobic, anaerobic, and acid fast bacilli. Patients below 10 years had rigid bronchoscopy as a routine.
Surgicalmanagement included resection of the middle lobe and/or lingula, mediastinoscopy, and VATS. Allpatients were followed up at 2 weeks, 3 months and every 6 months and then yearly for 1-4 years at the outpatient clinic.
Variables Group A (no. 39) Group B (no.45)Age (Mean) 5 ± 2.7 39.7 ± 14.2Sex (m:f) 18m:21f 24m:21fPresentationCough 39 (100 %) 41 (91.1 %)Wheeze 26 (66.6 %) 16 (35.5%)Sputum 17 (43.5 %) 26 (57.7%)Shortness of breath 10 (25.6 %) 22 (48.8 %)Recurrent infection 23 (58.9%) 10 (22.2 %)Hemoptysis 1 (2.5 %) 14(31.1 %)Chest pain 3 (7.6%) 5 (11.1 %)Weight loss 3 (7.6%) 16 (35.5 %)Pleural effusion 0 2 (4.4 %)Duration of symptoms before 3-48 mo 2-36modiagnosis 14.5 9.4(Range and mean)
Bothgroups show a long period between symptoms and intervention ranging from 2 months – 4 years. However, in patients presenting with hemoptysis or malignant etiology this period was short 1-3 months
Inthis report, the main etiological factor in group A causing MLS pathology was non- specific infection in 34 patients (87.1 %), 4 patients (10.2 %) were TB and one patient (2.5 %) had endobronchial hamartoma causing MLS. Ingroup B, 13 patients (28.8 %) were due to non-specific infection, 14 patients (31.1 %) due to TB and 18 patients (40 %) were due to malignant etiology.
Surgical intervention varies according to the pathology, Ingroup A, 36 patients (92.3 %) underwent middle lobectomy, 2 patients (5.1 %) underwent lingulectomy and one patient underwent staged left lower lobectomy followed 4 weeks later by middle lobectomy.
In group B, 33 patients (73.3 %) underwent middle lobectomy, 3 patients (6.6 %) underwent lingulectomy. Bilobectomy was done in 3 patients (6.6 %) when the tumor mass from the middle lobe crossed the fissure. 2 patients (4.4 %) underwent staged bilateral lobectomies bilateral bronchiectasis. Mediastinoscopy was done for 2 patients (4.4 %) to evaluate associated mediastinal lymph nodes that were positive for adenocarcinoma. VATS was done for 2 patients who had associated moderate pleural effusion to evaluate the pleura for possible malignant spread. Both patients had positive pleural nodules (adenocarcinoma).
In this series there was no morbidity or mortality; outcome varies according to the pathology. In group A, 25 patients (64.1 %) underwent middle lobectomy for a collapsed lobe. 14 patients (31.1 %) presented with bronchiectasis, 11patient underwent middle lobectomy, 2 patients underwent lingulectomy and 1 patient had bilateral staged lobectomy. Left lower lobectomy was primary targeted due to extensive disease, followed 4 weeks by middle lobectomy when patient symptoms didn’t improve dramatically. This group of patients with bronchiectasis had excellent improvement except for 1 patient who had mild recurrence of symptoms 3 years after the operation, and whose CT scan showed bronchiectatic changes at the apical segment of the right lower lobe, she was controlled by medical treatment.
In group B, 28 patients (62.2 %) had middle lobectomy due to collapse, and 17 patients (26.6 %) had resection for bronchiectasis. All had excellent outcome with control of symptoms at follow up that extended for 3 years. 18 patient in this group had malignant etiology, 14/18 patients underwent resection of the middle lobe and additional 3/14 had lower lobectomy. 4 patients were inoperable due to metastasis (2 patients with mediastinal lymph nodes and another 2 patients with malignant effusion). 10 patients (22.2 %) in this group survived 7-36 months with a mean of 17.7 ± 10.6, while 8 patients (17.7 %) exceeded 4 year follow up.
Middlelobe syndrome (MLS) is characterized by a spectrum of diseases from recurrent atelectasis and pneumonitis to bronchiectasis of the middle lobe. It has been described among all age groups
Inthis study 2/3 in both groups presented with atelectasis and 1/3 with bronchiectasis. Non- specific infection was present in 87.1 % of patients and 10.2 % had TB in group A. Malignancy was the main etiology in group B accounting for 40 % of patients and almost 30 % had TB.
Thepathological changes that led to MLS are either obstructive or non-obstructive. In this series 31 patients (36.9 %) had no obstruction on bronchoscopy (10 patients in group A and 21 patients in group B), and a deep fissures were noted at operation separating the middle lobe from both the upper and lower lobe and thus interrupting any collateral ventilation and explaining the collapse.
53patients (63 %) had obstruction on bronchoscopy ranging from partial (27 patients (32.1 %) in group A and 18 patients (21.4% in group B) to complete (2 patients in group A and 6 patients in group B) obstruction. Inthese 53 patients deep oblique fissure was complete in all cases; however in few patients 7/53 (13.2 %) the transverse fissure was incomplete.
The management of MLS is essentially conservative in pediatric age group particularly when early intervention is followed. However in our series patients were referred after failure of conservative treatment in 2/3 of patients and bronchiectasis in 1/3 of patients
The management in adult group is conservative in inflammatory category of this group of patients representing 27 patients (60 %), however due to chronicity and hemoptysis in 14 patients (31.1 %) surgery was indicated. In the malignant subgroup of the adult group, 18 patients (40 %) presenting with malignancy were managed surgically. In the malignant subgroup 14/18 patients (77.7 %) were operable and underwent lobar resection, 4 patients (22.2 %) were inoperable due to distant metastasis.
Surgical management of MLS is safe. Theoutcome depends on the etiology and age, in this series inflammatory causes carries the best prognosis, whereas malignant causes have unfavorable prognosis.