Local Anesthetic Thoracoscopy for Undiagnosed Pleural Effusion

Summary

Local anesthetic thoracoscopy (LAT) is essential for diagnosing recurrent, undiagnosed pleural effusion when a guideline-based workup fails to provide a specific cause. LAT can be performed as a day-case procedure by chest physicians. Here, we present a step-by-step approach for a successful and safe procedure.

Abstract

Local anesthetic thoracoscopy (LAT) is a minimally invasive diagnostic procedure gaining recognition among chest physicians for managing undiagnosed pleural effusions. This single-port procedure is conducted with the patient under mild sedation and involves a contralateral decubitus position. It is performed in a sterile setting, typically a bronchoscopy suite or surgical theater, by a single operator with support from a procedure-focused nurse and a patient-focused nurse.

The procedure begins with a thoracic ultrasound to determine the optimal entry point, usually in the IV-V intercostal space along the midaxillary line. Lidocaine/mepivacaine, with or without adrenaline, is used to anesthetize the skin, thoracic wall layers, and parietal pleura. A designated trocar and cannula are inserted through a 10 mm incision, reaching the pleural cavity with gentle rotation. The thoracoscope is introduced through the cannula for systematic inspection of the pleural cavity from the apex to the diaphragm. Biopsies (typically six to ten) of suspicious parietal pleura lesions are obtained for histopathological evaluation and, when necessary, microbiological analysis. Biopsies of the visceral pleura are generally avoided due to the risk of bleeding or air leaks. Talc poudrage may be performed before inserting a chest tube or indwelling pleural catheter through the cannula. The skin incision is sutured, and intrapleural air is removed using a three-compartment or digital chest drainage system. The chest tube is removed once there is no airflow, and the lung has satisfactorily re-expanded. Patients are usually discharged after 2-4 h of observation and followed up on an outpatient basis. Successful LAT relies on careful patient selection, preparation, and management, as well as operator education, to ensure safety and a high diagnostic yield.

Introduction

The incidence and prevalence of pleural diseases are increasing worldwide, especially pleural effusions, which have more than 50 recognized causes^1,2. Pleural malignancy is the leading cause of recurrent pleural effusion, mostly due to metastases from extrapleural lung, breast, or lymphoma malignancies³. Existing guidelines recommend pleural biopsies if the medical history, physical examination, radiology, and pleural tap for cytology, culture, and biochemistry fail to provide a diagnosis⁴. Pleural biopsies can be obtained either image-guided or under direct visi....

Protocol

The following protocol will describe how to perform LAT in a clinical setting. The protocol is in accordance with the clinical practice and guidelines of the authors' hospitals (Odense, Næstved, Lleida, Bristol, and Preston). Written informed consent is obtained from the patient prior to the procedure. The main inclusion criteria for the procedure is recurrent pleural effusion of unknown cause, despite guideline-based work-up. Exclusion criteria include complete obliteration of the pleural space due to adhesions, skin infection at the site of entry, respiratory failure, cardiac instability, and uncorrectable coagulopathy.

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Results

The described LAT technique using either the rigid or semirigid thoracoscopes (Figure 1 and Figure 2) enables the operator to perform conclusive biopsy sampling from the visceral pleural (Figure 3) with a diagnostic yield of 93% in a large systematic review on more than 5000 procedures (Table 1 and Supplementary File 1) (rigid: 93% [95% confidence interval 91%-95%]; semirigid: 93% [89%-97%])

Discussion

This article provides a practical approach for performing LAT.

A single randomized trial compared rigid with semirigid LAT and found no differences concerning diagnostic yield or safety¹⁵. Evidence on how to optimize the critical steps is sparse. A group of one of the authors suggested eight critical steps for semirigid LAT and presented a competence checklist for learning LAT in a phantom based on their own experiences, narrative reviews^8,<.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Chest tube			16-24F
Forceps			narrow tip, straight or curved
Indwelling pleural catheter	Rocket Medical plc.	R55400-16-MT	or PleurX (from Becton Dickinson) or similar
Local anaesthetics			20 mL of lidocaine 1% (or mepivacaine 2%) ± adrenaline
Non-absorbable suture			Eg. Dafilon 2/0
Rigid thoracoscope	Karl Storz GmbH	Hopkins-II	with forceps 26072A and cannula+trocar 30120 NOL (or similar from eg. Richard Wolf GmbH)
Scalpel			triangular
Semirigid thoracoscope	Olympus	LTF-160	with forceps FB-420K and cannula+trocar N1002130