HODA BAHR, MOHAMED EL-SHAFEY, MOHAMED HANTERA, GEHAN ABO-EL MAGD AND AHMED H. EL-BATSH Ultrasound Guided Needle Pleural Biopsy in Patients with Undiagnosed Pleural Effusion

Introduction Exudative pleural effusions are frequently encountered in pulmonary practice. Determination of a specific diagnosis can represent a major challenge. Biopsy of the pleura may be necessary in cases where thoracentesis fails to provide a diagnosis in a suspected exudative effusion, or in cases of pleural thickening or pleural masses where histology is required to make a diagnosis.

US of the pleura Blind pleural biopsies have varied sensitivity from 24%-66% using Abrams needle. CT and US can be used safely as image guidance for pleural biopsies, with higher percent of sensitivity and specificity.

US of the pleura US is very useful in guiding invasive pulmonary procedures, especially for lesions on the chest wall, pleura and peripheral lung. Invasive procedures are often performed in pleural puncture for diagnosis purposes, chest tube installation, pleural biopsy and superficial lung tumors biopsy. The use of US will increase the success of the procedures and minimize side effects.

US of the pleura Normal pleural membranes are too thin to be visualized even by high-resolution US. The interface between the normal visceral pleura and underlying lung produces the “pleural stripe” which is a thin echogenic line projecting internal to the ribs. It moves craniocaudally with respiration on US.

US of the pleura In the presence of pleural effusion, the visceral pleura is visible as an echogenic line thinner than the previously mentioned pleural interface. Focal pleural masses associated with an effusion are readily seen and biopsied with US guidance.

US of the pleura

US is more sensitive (5 ml fluid detectable) than decubitus radiography. Pleural effusions typically appear as triangular anechoic collections immediately above the diaphragm that change shape with respiration and outline the underlying echogenic, airless posterior costophrenic sulcus. Portable chest US examination is particularly useful to detect and quantify pleural fluid collections in supine critically ill patients

US of the pleura Various types of the ultrasound transducers (a. linear array transducer, b. curvilinear transducer, c. phased array transducer) The selection of transducer sizes is very essential in real-time US examination.

Type of TTNB

Aim of the present work To identify the role of percutaneous ultrasound guided needle biopsy in patients with undiagnosed pleural effusion.

Patients and Methods This study was conducted on 30 patients: Patients fulfilled the criteria of exudative pleural effusions with uncertain diagnosis by routine radiological, chemical, bacteriological and cytological methods.

Inclusion criteria : Chest X-ray or CT chest or sonar evidence of pleural effusion or pleural lesion. The cause of pleural effusion was not established by chemical, bacteriological or cytological methods. Pleural lesion if present must be more than 2 cm in diameter if present.

Exclusion criteria: Clinical or radiological features of empyema. Patients with transudative pleural effusion. Patients have bullous emphysema. Patients on anticoagulant therapy. Uncooperative patients.

The patients were divided into 3 groups: Group A: Patients with undiagnosed pleural effusion without any underlying pleural or lung lesions. Group B: Patients with undiagnosed pleural effusion with underlying pleural lesions and without lung lesions. Group C: Patients with undiagnosed pleural effusion with underlying pleural lesions and lung lesions.

US guided needle aspiration biopsy: Patient was kept fasting at least 6 hours before biopsy. A sterile field was created. The transducer which was used for biopsy was the convex one with a frequency of 2–5 MHz.

US guided needle aspiration biopsy: Patient was allowed to sit exposing his back. Local anesthesia in the form of subcutaneous injection of xylocaine 2% is injected. Core biopsies of pleural or lung lesions were performed using tru cut needle (Gauge 18) with a specimen notch of 20 mm.

US guided needle aspiration biopsy: Immediate post-procedure care: The incision site was re-examined by means of US immediately after the procedures for suspected pneumothoraces. Chest X-ray was done for all patients. All patients were observed for at least 1 h before discharge and complications were noted.

The patients were subdivided into 3 groups: Group A: Included 7 (23.3%) patients with undiagnosed pleural effusion without any apparent underlying pleural or lung lesions. Group B Included 10 (33.3%) patients with undiagnosed pleural effusion with underlying pleural lesions and without apparent lung lesion. Group C Included 13 patients with undiagnosed pleural effusion with underlying pleural lesions and lung lesions (43.3%).

Histopathological diagnosis of all studied patients (n=30) 24 cases out of 30 were diagnosed Malignant (17) Mesothelioma(9) Bronchogenic carcinoma with pleural metastasis(8 ) Inflammo -tory(7) Tuberculous(2) Parapneumonic(2) Inflammatory mass(3)

In group A 4 cases out of 7 cases were diagnosed(57.2%) 1case tuberculous 1 case mesothelioma 2cases metastatic adenocarcinoma

In group B 10 cases out of 10 cases were diagnosed(100%) 1case tuberculous 8 case mesothelioma 1cases metastatic adenocarcinoma

In group C 10 cases out of 13 cases were diagnosed(76.9%) 5case Bronchogenic carcinoma with pleural metastasis 3 case inflammatory masses 2cases Parapneumonic effusion

Pathological tissue characterization. 4 cases 16.7% 8 cases 33.3% 2 cases 8.3% 10 cases 41.7% 6 cases 20% non

Complications of ultrasound guided transthoracic biopsy 3.3%)) 1 case Bleeding at the site of procedure 1 case (3.3%) Shock 6.7%)) 2 cases Pneumothorax

Discussion The lower rate of adverse events during pleural biopsy taking in the present study confirms that the lesion size and needle type chosen in this study were adequate. US has the inherent safety advantage of visualizing only lesions not shielded by air-containing tissue. Aerated lung is therefore not transversed with the biopsy device, which makes pneumothorax and air embolus unlikely when a closed cutting-needle system is used.

Sensitivity, specificity and accuracy of US transthoracic pleural needle biopsy in the studied groups Accuracy % Specificity % Sensitivity % Group A 100 Group B Group C Total

Advantage of US guided biopsy Rapid and convenient Detecting the pleural masses in real-time and making needle biopsies simultaneously, and No radiation exposure. Practically, some patients with pleural masses and pleural effusions often had complaints of dyspnea and chronic cough; therefore, it was difficult or impossible for these patients to lie in bed for a thoracic CT examination or fluoroscopic and CT- guided needle biopsies.

Discussion Lesions were considered suitable for US-guided biopsy if there were in contact with chest wall for at least 2 centimeter regardless of their size and location. Location behind a rib was considered to be a contraindication.

Discussion Small lesion less than 2 cm or pleural effusion without underlying pleural masses were found to be difficult with a high failure rate in taking the biopsy. So, this might be the cause of undiagnosed cases in the present study especially most of the undiagnosed patients were in(Group A) who had undiagnosed pleural effusion without any underlying pleural or lung lesions.

Discussion However, the yield of 80% in the present study suggests that US assistance might substitute CT guidance for lesions ≥20 mm in diameter, irrespective of the presence of a pleural effusion. Moreover, physician- operated US is far more accessible than CT in many peripheral health-care facilities, and a simple and low-cost diagnostic technique is particularly welcome in regions with high asbestos exposure.

CONCLUSIONS US-guided transthoracic biopsy allows needle placement and biopsy taking during a single breath hold, which decreases the time the needle stays across the pleura with a multi planar capability. Real-time US visualization allows accurate needle placement, shorter procedure time, and performance in debilitated and less cooperative patients.

CONCLUSIONS Tru-cut needle is simple with a high yield in patients with undiagnosed pleural diseases especially for patients with pleural tumors, thickened pleura, and small amount of pleural effusion.