An Update on Bronchial Blockers During Lung Separation Techniques in Adults

Techniques for one-lung ventilation (OLV) can be accomplished in two different ways. The first involves the use of a double-lumen endotracheal tube (DLT). The second method involves blockade of a mainstem bronchus to allow lung collapse distal to the occlusion (bronchial blockers) (1–3). In 1936, Magill (4) achieved bronchial blockade using a long tube with an inflatable cuff at its distal end that was advanced alongside a single-lumen endotracheal tube. Since then, more devices have been introduced including: 1) the Fogarty vascular embolectomy catheter (5) [Edwards Lifesciences, Irvine, CA]; 2) a Wiruthan bronchial blocker (6) [Willy Rusch AG, Kernen, Germany]; 3) a single-lumen endotracheal tube with an enclosed bronchial blocker (Torque Control Blocker Univent®) [Vitaid Lewinston, NY](7); and 4) the wire-guided endobronchial blocker [Arndt blocker; Cook® Critical Care, Bloomington, IN](8). Although DLTs are still the most common device used during lung separation techniques (9), bronchial blockade technology is on the increase, and in some specific clinical situations it can offer more advantages over the DLTs. This review addresses current concepts on the use of bronchial blockers as an alternative to achieve lung separation in adults. Use of the Fogarty Embolectomy Catheter as a Bronchial Blocker The Fogarty occlusion embolectomy catheter (5) is a device designed specifically to be used as a vascular tool; however, there are well documented reports of its use in successful bronchial blockade to achieve lung isolation. Common sizes of the Fogarty occlusion catheter used in adults for bronchial blockade include: number 6.0, 8/14, or 8/22 French (F) catheter, which has a length of 80 cm. The number 8 refers to the catheter size and the numbers 14 and 22 correspond to the inflated balloon diameter in millimeters. The occlusion balloon of the Fogarty catheter is considered a high-pressure, low-volume cuff, that requires between 0.5 to 10 mL of air to achieve occlusion of a bronchus. The Fogarty catheter has an incorporated stylet that can be preshaped at the distal end to facilitate its guidance into the left mainstem bronchus. The Fogarty occlusion catheter has the following advantages: 1) it can be advanced through the lumen of an existing single-lumen endotracheal tube; 2) it can be used as a rescue device when difficulties to position a right- or left-sided DLT are encountered in patients who are already intubated with a DLT and are in the lateral decubitus position. By advancing the Fogarty catheter inside the endobronchial or endotracheal lumen of a DLT, lung isolation can be obtained (10,11). 3) Fogarty catheters have been used as a selective lobar bronchial blocker in patients with bronchopleural fistula where placement of this device along with a DLT reduced the amount of leakage and led to improvement of gas exchange (12). 4) Fogarty catheters also have been used as a double endobronchial blocker to collapse the right lung with two independent Fogarty catheters to facilitate a right-sided lung isolation during selective lobar blockade (13). 5) Fogarty catheters have been used in patients with tracheostomies requiring OLV. 6) Finally, they can be used nasotracheally if oral airway anatomy is distorted and OLV is required. The disadvantages of the Fogarty occlusion catheter for use as a bronchial blocker are: 1) the Fogarty catheter is a vascular device, and not designed as a bronchial blocker; 2) the Fogarty catheter is made of natural rubber latex, which is contraindicated in patients with latex allergy; 3) there is a lack of a communicating channel in the center, therefore suction or oxygen insufflation is not possible; 4) there is a lack of guidewire device. Although its stylet facilitates insertion into a bronchus, it cannot be coupled with a fiberoptic bronchoscope; 5) an air leak from the breathing circuit can be a common problem, specifically when the Fogarty catheter is placed inside the single-lumen endotracheal tube. However, this problem can be prevented when the Fogarty is placed externally to the endotracheal tube. Although clinical reports of comparison with other blockers are lacking, there is a large series of >200 cases by a single author in which the Fogarty occlusion catheter was preferentially used for a left-sided thoracic surgery with apparently positive results (5). There are also some isolated reports of use in patients with difficult airways requiring OLV (10–13). Placement and Positioning of Fogarty Occlusion Catheters The Fogarty occlusion catheter (8/14F) can be lubricated with silicone spray (use with caution because it can become highly flammable) or lubricating jelly and then passed through a single-lumen endotracheal tube. Its guidance is facilitated while advancing the fiberoptic bronchoscope next to it. Another alternative when placing a Fogarty catheter is to use it as an independent device, passed during direct laryngoscopy as a separate device externally to the single-lumen endotracheal tube. Once the Fogarty catheter is introduced into the targeted bronchus, the stylet is removed and the catheter balloon is inflated under direct vision with the fiberoptic bronchoscope. The optimal position of the Fogarty occlusion catheter is one that allows complete blockade of the bronchus without any detectable air leak. When the Fogarty occlusion catheter is placed in the left mainstem bronchus, it is in the ideal position so that the outer surface of the cuff is located approximately 10 mm below the tracheal carina inside the left bronchus. In most circumstances, for a right-sided mainstem bronchus occlusion, blocker cuff inflation should include the right-upper lobe. This approach is depicted in Figure 1A. Once the Fogarty occlusion catheter is in its optimal position, confirmation of placement with the fiberoptic bronchoscope must be done in the supine and lateral decubitus positions. Figure 1, A and B shows the optimal position of the Fogarty occlusion catheter. After placement and positioning is completed, to prevent an air leak between the connector of a single-lumen endotracheal tube and the elbow connector of the breathing circuit, a modified 9F arrow-Flex sheath connected with a twist-lock device makes a perfect airtight seal when used with the diaphragm of the Portex bronchoscope swivel connector (14) (Portex Inc., Keene, NH). In addition, two different alternatives can be used to prevent an air leak between the breathing circuit and the endotracheal tube with the Fogarty catheter passing through the endotracheal tube: 1) the cap of the diaphragm on a Portex swivel adaptor is perforated allowing passage of the Fogarty catheter. Once the Fogarty catheter is correctly positioned in the bronchus, the cap is advanced over the Fogarty and inserted into its slot in the swivel adaptor thereby providing an airtight seal; 2) the use of the Arndt multiport adaptor permits independent passage of any blocker and fiberoptic bronchoscope. The multiport adaptor from the Arndt blocker can be obtained separately from its manufacturer (Cook® Critical Care).Figure 1: A, Fogarty occlusion catheter; the optimal position of the Fogarty in the right, and (B) the left mainstem bronchus. The arrow indicates the outer surface of the inflated balloon (A and B). 1 = tracheal carina, 2 = right mainstem bronchus, 3 = right upper lobe bronchus, and 4 = bronchus intermedius.Complications of the Fogarty Occlusion Catheter Because of the uncommon use of the Fogarty catheter as a bronchial blocker, there are no reported complications with the Fogarty occlusion catheter in adults. The tip of the Fogarty catheter is very soft because the wire stylet terminates at least 1 cm proximal to the end of the catheter. Therefore, airway rupture with the Fogarty catheter is very unlikely especially if the catheter is advanced under direct fiberoptic visualization. However, forcing the introduction of a Fogarty with the stylet in place can carry the risk of airway rupture. Also, the potential for inclusion in the stapling line exists, especially when this device is used as a selective lobar blocker. Single-Lumen Endotracheal Tube with an Enclosed Bronchial Blocker (Univent®) and the Torque Control Blocker (Univent®) In 1982, Inoue et a1. (15) introduced a new device for OLV. They used a single-lumen endotracheal tube with an incorporated bronchial blocker (the original Univent®) so that when OLV is no longer needed the tube can be left in situ (for postoperative mechanical ventilation). The Univent® and its newest version, the Torque Control Blocker Univent® (TCBU), introduced in 2001, have a shape similar to that of a standard endotracheal tube. Within the Univent® unit, there is a channel enclosing a moveable bronchial blocker that can be used to block the left, the right, or any specific secondary bronchi. The enclosed bronchial blocker is made of flexible nonlatex material, and has a flexible shaft (TCBU) which is easier to guide into a bronchus. It has a high-pressure, low-volume cuff that requires approximately 2 mL of air to produce an airtight seal if selective lobar blockade is used (16–18), or 4–8 mL of air if total blockade of the bronchus is desired (19,20). The resting volume and diameter of the bronchial blocker cuff of the Univent® is 2 mL and 5 mm, respectively (19), and for the TCBU, the resting volume is 3 mL (personal communication from the manufacturer). The bronchial blocker has a small lumen for suctioning and should be closed before insertion. Current sizes available for the TCBU in adults range from 6.0 to 9.0 mm inner diameter. Because of the oval shape of the airway lumen, the effective internal radius is reduced. Also, the channel that encloses the bronchial blocker has a diameter of 2 mm but increases the anterior-posterior external diameter of the Univent®, which makes it larger than a single-lumen endotracheal tube of corresponding internal diameter (ID). Table 1 depicts the sizes available for Univent® tubes and compares those to a single-lumen endotracheal tube and DLTs. An advantage of the Univent® is its utility in patients in whom the airway is considered difficult for direct laryngoscopy (21–26), and during unanticipated difficult endotracheal intubation (27). The Univent® has been used in tracheostomy patients who require OLV (28,29).Table 1: Comparison of Outer Diameter (OD) and Internal Diameter (ID) of Single-Lumen, Univent®, and Double-Lumen Endotracheal TubesOther features of the Univent® tube are its efficacy as a selective lobar blocker to improve oxygenation (16–18). Because of its relative ease of placement, the Univent® has been used in patients with hemoptysis or bleeding diathesis, and can be used during rapid sequence induction during OLV (30,31). The Univent® tube has been effective with different modalities of ventilation including jet ventilation during sleeve pneumonectomy (34,35). It can be converted to a conventional single-lumen endotracheal tube by deflating and withdrawing the bronchial blocker. Placement and Positioning of the TCBU The TCBU has two compartments, a large lumen for air/oxygen passage through the anesthesia breathing circuit, and a small lumen in the middle of the enclosed and movable bronchial blocker. The inner diameter of the bronchial blocker is 2 mm. This blocker can be advanced >10 cm beyond the main body. Before use, the bronchial blocker of the Univent® is lubricated to facilitate passage; the endotracheal cuff should also be lubricated. The enclosed bronchial blocker must be retracted into the standard lumen of the tube. Conventional endotracheal tube placement is performed, and then a fiberoptic bronchoscope is passed. Under direct vision, the enclosed bronchial blocker is advanced into the targeted bronchus. When a Univent® tube is used, the enclosed bronchial blocker must be directed into the bronchus of the surgical side, where the lung collapse occurs. The optimal position for the Univent® tube in either the right- or left-side bronchus is when the bronchial blocker cuff is fully inflated with no air leaks detected. Fiberoptic bronchoscopic examination will show that the proximal or outer surface of the cuff is located just below the tracheal carina, usually ≥5 mm inside the desired bronchus. The end of the Univent® tube should be at least 1–2 cm above the tracheal carina. Figure 2, A and B show the TCBU and its optimal position for a right or left bronchus seen through the fiberoptic bronchoscope. Because of the relatively short distance between the tracheal carina and the right upper bronchus, the Univent® can be used as a selective blocker by advancing it into the bronchus intermedius and thereby selectively collapsing the right-middle and right-lower lobes (16–18), specifically in case of hemorrhage of these lung segments.Figure 2: A, Torque Control Blocker Univent®; the optimal position of the Univent® in the right, and (B) the left mainstem bronchus. The arrow indicates the outer surface of the inflated blocker cuff.Ventilation Modalities that Apply to the TCBU can and one to improve oxygenation is by positive ventilation can be to the Univent® tube when the suction cap of the enclosed bronchial blocker is and a small connector of a single-lumen endotracheal tube is and then a standard is connected The Univent® tube has also been used during jet ventilation in a with a tracheal carina by using the enclosed bronchial blocker lumen to with the of the (34,35). different alternatives for selective ventilation with or can be to the Univent® tube. and with the TCBU A of complications have been reported with the original of the from the inner when the connector was to the tube in of silicone into the bronchus Also, a in the TCBU has been reported in which a of the blocker cap connector in 2 of the first tubes used to achieve lung separation because of anatomy or lack of seal the bronchus has also been reported of the enclosed bronchial blocker into the stapling line has been reported during a right upper Therefore, communication with the surgical the of a bronchial blocker in the surgical is potential and with the bronchial blocker cuff of the Univent® was the cuff of the bronchial blocker was inflated the tracheal lumen a of with the potential risk of has been reported suctioning of the lung by the bronchial blocker Therefore, if suction is used to facilitate lung it should be done for a at and with Another reported with the Univent® insertion of the blocker, passing it beyond the left bronchial carina, lung rupture and Therefore, require fiberoptic guidance during placement of the bronchial blocker. Another common problem with the Univent® can be and of the bronchial blocker while the from a supine to a lateral decubitus position. Therefore, cuff of the Univent® bronchial blocker the original placement and before the into a lateral decubitus position. After the is in the lateral decubitus position, then of the bronchial blocker is Also, can during surgery while surgical of the bronchus Therefore, fiberoptic is the method of to achieve optimal position of the Univent® as well as to Although with the Univent® more when with left-sided DLT one that when the Univent® was used for a right-sided thoracic it was to right-sided DLT with to in 3 of patients in the right-sided DLT 5 of patients who right-sided Therefore, clinical that can be used for right-sided bronchus with if fiberoptic is used while positioning this device. Blocker Another to achieve lung separation is the Arndt blocker which is considered an independent bronchial blocker. The Arndt blocker is to a or 9F catheter that is available in and with an inner lumen mm of diameter. the distal end of the catheter, there are incorporated to facilitate lung are in the 9F Arndt blocker This bronchial blocker has a cuff with either an or in the cuff from to shape to facilitate its use for the right mainstem bronchus By using the cuff on the right bronchus, complete blockade can be achieved without inclusion of the right upper bronchus, the and cuff not block the right bronchus The inner lumen a flexible wire passing through the proximal end of the catheter and to the distal end and then it as a small flexible Figure 3 the Arndt blocker and its multiport The of the Arndt blocker is coupled with the fiberoptic bronchoscope and as a guidewire to the blocker into a bronchus. the Arndt blocker to and allow with the fiberoptic the endotracheal tube should be for a blocker, use a single-lumen endotracheal and for the larger Arndt blocker use at least a single-lumen endotracheal The wire-guided endobronchial blocker and the multiport 1 = Fiberoptic bronchoscope 2 = blocker 3 = endotracheal tube connector and 4 = ventilation are advantages to using the Arndt blocker over the DLTs or TCBU in patients who are already intubated who a difficult airway or require OLV during to the Another advantage of the Arndt blocker is that it can be passed through a tube in patients who require intubation and in patients with airway or in patients with tracheostomy and OLV Also, it can be used as a selective lobar blocker in patients with pneumonectomy who require selective ventilation or as a selective blocker during bleeding Because the Arndt blocker requires a single-lumen endotracheal it the and the for tube exchange if mechanical ventilation is in the postoperative Another advantage of the Arndt blocker is its to allow ventilation through the inner by a of a single-lumen endotracheal tube connector with the Inc., during OLV with the use of the Arndt blocker include the that it is difficult to use when a 9F blocker is passed over a single-lumen endotracheal tube. Another is with the wire-guided it is it cannot be and of the blocker can be difficult especially during left mainstem bronchus a new Arndt blocker is Also, the small diameter of the suction channel increases the for the lung to when with the TCBU Placement and Positioning of the Blocker The Arndt blocker is a single that is passed through a single-lumen endotracheal tube. Before the blocker balloon is then fully The is lubricated with silicone spray or lubricating It is that the shape for a right-sided mainstem bronchus intubation or a selective lobar blockade is and the cuff should be to left-sided mainstem because its shape into the left bronchus. prevent of the blocker cuff insertion through the multiport the balloon must be fully before insertion through the blocker Also, the blocker should be fully before insertion of the The placement of the Arndt blocker involves placing the endobronchial blocker through the endotracheal tube and using the fiberoptic bronchoscope and to direct the blocker into a mainstem bronchus. The fiberoptic bronchoscope has to be advanced so that the Arndt blocker will the bronchus while it is Once the cuff is below the of the bronchus, the fiberoptic bronchoscope is and the cuff is fully inflated with mL of if selective lobar blockade is or mL of air if total bronchial blockade is to of the bronchus. a right mainstem bronchus the Arndt blocker can be advanced independent of the its into the right main bronchus under fiberoptic visualization. After the is to the lateral decubitus position, bronchoscopic confirmation is to that the cuff of the Arndt blocker is still on a the optimal position of the Arndt blocker is achieved in the supine position, the cuff should be the blocker advanced approximately 1 cm to the during the position, and then placement in the lateral decubitus position. The can then be to the channel into a suction to lung It is to the to inclusion during the stapling line of the bronchus. The optimal position of the Arndt blocker in the left or in the right bronchus is achieved when the blocker balloon outer surface is seen with the fiberoptic bronchoscope at least 5 mm below the tracheal carina on the targeted bronchus and the seal is A and B show the position of the Arndt blocker in the right or left mainstem bronchus. shows a selective lobar blockade with the Arndt blocker when positioned into the bronchus A, endobronchial blocker the optimal position of the Arndt blocker in the right, (B) the left mainstem and as a selective lobar blocker when positioned into the bronchus 1, The arrow indicates the outer surface of the inflated Arndt blocker 2, a of the right upper lobe and with the Blocker Because of its relatively introduction there are not reports of complications with the Arndt blocker. There is a of balloon of the Arndt blocker that when the blocker was removed through the multiport blocker this was from the single-lumen endotracheal tube before into the In the from the manufacturer (Cook® Critical that of use, the Arndt blocker cuff must be and the blocker along with the multiport connector and not through the blocker A common with the Arndt blocker is a reported more of when with the TCBU In when with other it was that an optimal position in the supine position, the Arndt blocker was more to the into a lateral position of a right or left mainstem bronchus blocker was of a Single-Lumen Endotracheal Tube and the Univent® Tube In one of the advantages of a single-lumen endotracheal tube and the Univent® blocker is that they not have to be at the end of thoracic surgery because so can airway or potential risk for the However, some have to be when a tube in the OLV is no longer including: the of the the outer and In a by and the external of tube was on the main of the tube endotracheal tubes and and Univent® tube sizes and at the of the distal of the tracheal results that tube a on the of and for tubes the single-lumen endotracheal tube an external to any Univent® tubes Also, they reported that the of Univent® tubes was larger when with single-lumen endotracheal tubes with corresponding numbers Although the of and Univent® tubes are larger than those of and single-lumen endotracheal the was Therefore, the sizes of Univent® tubes as to have a and should be with an single-lumen endotracheal tube if postoperative mechanical ventilation is Bronchial a for a DLT After the and of bronchial blocker, some can be separation is 1) to facilitate surgical in and surgery the 2) to facilitate gas exchange to the other bronchus as with a bronchopleural 3) to prevent to the lung or 4) during the use of specific of lung ventilation or of this can be with bronchial DLTs are used in most cases that require OLV In a DLT placement can be including difficulties in the tube the potential for the tracheal cuff during intubation requiring and difficulties in placement or Therefore, a bronchial blocker be an when difficulties are encountered a DLT as in a of short a bronchial blocker be over Table 2 depicts a of specific in which a bronchial blocker can be 2: of Bronchial the advantages that a bronchial blocker can offer over a DLT, some have to be In a and that left-sided DLT to place of when with the TCBU, or the Arndt blocker, also that lung collapse is with the DLT with the TCBU or the Arndt blocker. Also, the of the patients who a bronchial blocker suction to lung In the of was when the Wiruthan bronchial blocker was with the left-sided DLT during The number of needed to place a DLT or a bronchial blocker two in supine and one in decubitus The most is the of the surgical In the and OLV was achieved either with a DLT or bronchial blocker, surgical was the during thoracic of the lung to for any air no with to the lung difficulties the lung encountered in the bronchial blocker Therefore, it is that bronchial blockers can be used in cases that require into 1) bronchial blockers require longer for placement, 2) suction to lung collapse be and 3) the use of fiberoptic bronchoscope in the that of the blocker occurs. should become with this technology and be to use it when of a difficult airway during OLV or selective lobar In the case of lung or of to the other lung with bleeding or where a large suction lumen is then use of a DLT should be the for lung Although Univent®, and Arndt blockers have specifically in patients with difficult airways that require there is still for the ideal bronchial blocker should have a channel with a diameter large to allow to be without and without the of the single-lumen endotracheal tube. the manufacturer of the TCBU has made the bronchial blocker available as a separate device, and it can be used through a single-lumen endotracheal tube. This with its multiport Cook® Critical has a new independent blocker similar to the Arndt blocker without the for of these devices have been The current use of bronchial blocker by clinical that bronchial blockers should be available in any that lung separation Finally, it is to that positioning and of of bronchial blockers are with the use of fiberoptic in a then lateral decubitus position, or an occurs. In addition, the and use of bronchial blockers in the be and are not the of this