Right ventricular endomyocardial biopsy procedures are most commonly performed via the right internal jugular vein. Patients usually fast for 8 hours prior to the procedure, but sedative premedications are generally not required for this outpatient procedure. Monitoring during the procedure includes continuous electrocardiogram, pulse oximetry, and blood pressure. For patients who are in decompensated heart failure, continuous arterial pressure monitoring (using a small-bore catheter or a commercially available noninvasive instrument) is recommended.

The patient’s head is turned 30° to 45° to the left to facilitate evaluation and preparation of the venous cannulation site. The internal jugular is located lateral to the carotid artery, within the anterior triangle formed by the sternal and clavicular head of the sternocleidomastoid muscle and top of the clavicle (Figure 26.4). These anatomical features can be identified more easily by having the patient briefly lift his or her head just off the table. Internal jugular venous cannulation should be attempted in the middle third of the triangle outlined by the landmarks noted above. This allows compression of venous or arterial structures should bleeding persist after the procedure or if carotid artery puncture
occurs during the procedure. In addition, this higher location in the anterior triangle lessens the risk of pneumothorax. If the location of the internal jugular vein is not readily apparent, we routinely evaluate the neck vasculature echocardiographically, using a 7.5-MHz dedicated sector scanner (Site Rite, Dynamax Corporation, Pittsburgh, PA) or a conventional echo transducer encased in a sterile sheath. The jugular vein can be distinguished from the more medial carotid artery by location, the pulsatility of the artery, and the compressibility of the vein (Figure 26.5). Use of echo guidance has been demonstrated to increase the frequency of successful vein cannulation, decrease access time, and decrease complication rates.¹⁴,¹⁵

In order to minimize discomfort at the entry site, topical lidocaine cream can be applied at least 1 hour prior to the procedure. After the patient’s landmarks have been identified, the neck is prepared with a standard povidone-iodine and alcohol preparation. The field is isolated using sterile towels and/or plastic drapes. An ether screen or similarly fashioned device can be used to isolate this area and to protect the patient’s face from the drapes. Successful puncture of the internal jugular is facilitated by distension of the vein—in patients with low venous pressure or a small internal jugular vein, this can be achieved by placing the patient in a headdown Trendelenburg position, elevating the legs on a wedge, or having the patient perform a Valsalva maneuver during needle advancement.

A 25-gauge needle is used to apply a small intradermal bleb of 2% Xylocaine at the site of planned sheath entry. A 22-gauge needle is then used to anesthetize the area from the superficial bleb toward the internal jugular vein. After the area is successfully anesthetized, a small (2 mm) incision is made at the superficial site of initial infiltration with
a no. 11 surgical blade. The incision is then expanded with the tip of a mosquito clamp to ensure that the skin will accommodate the 7F venous sheath. In a classic approach, the 22-gauge anesthesia needle is directed toward the anticipated venous pathway at an angle of approximately 30° to 40° from vertical and 20° right of the sagittal plane and is advanced in small increments, aspirating before infiltration of small amounts of lidocaine to provide local anesthesia. Excess lidocaine infiltration should be avoided, since it may result in venous compression or infiltration of vocal cords or carotid sheath resulting in transient hoarseness or Horner syndrome.

Once venous blood is aspirated, indicating entry into the internal jugular vein, the operator notes the position and direction of the needle, and a second 18-gauge singlewall puncture needle with syringe is advanced parallel to the “finder” needle. Continuous aspiration is applied as the needle is advanced in small increments, particularly in individuals with small internal jugular veins or a low central venous pressure. Usually the “give” of the vein wall is palpable, even before blood return is evident. A J-tip guidewire is then introduced, followed by the necessary sheath.

If the initial attempts at venous entry are unsuccessful, the probing needle is retracted to just beneath the skin level and redirected more laterally. If venous return is still not achieved, the needle may be directed more medially (toward the plane of the carotid artery). Should arterial puncture occur, the probing needle and syringe will spontaneously fill with well-oxygenated blood, and the needle must be removed and compression applied for 5 minutes or until hemostasis is achieved. As described above, this problem can be avoided by using echo guidance when the initial puncture attempt is unsuccessful.

An alternative approach is to use a 21-gauge micropuncture needle and a micropuncture kit (Figure 26.6) as the deep anesthesia, probing, and definitive entry device for internal jugular vein cannulation. The needle is very atraumatic and accepts a 0.018-inch stainless steel or nitinol guidewire over which a special 4 or 5 French coaxial hydrophilic-coated double dilator is advanced. Once this has entered the jugular vein and superior vena cava, the inner cannula and 0.018-inch guidewire are removed and a conventional 0.035-inch guidewire is inserted through the outer cannula. The cannula is then removed, and a 7 or 8 French self-sealing sheath is inserted over the guidewire. This is facilitated by passing the wire from the superior vena cava, across the right atrium, and into the inferior vena cava, avoiding runs of ventricular ectopy seen when the wire tip enters the right ventricle. Once the sheath is in the appropriate position, the guidewire and the dilator are removed, the sheath is aspirated and flushed, and the heart biopsy procedure can proceed. To minimize blood losses and the risk of air aspiration, the needle hub and the hub of the dilator sheaths should be occluded with a gloved finger during guidewire and sheath exchanges. A further alternative is to use a micropuncture vascular access Glidesheath kit, which includes a 21-gauge needle, a 0.021-inch hydrophiliccoated or nitinol guidewire, and a 6F sheath (Terumo Interventional Systems, Ann Arbor, MI). After insertion of the sheath, the biopsy can be performed using a 6F bioptome. The use of sheaths with hemostatic valves is preferred, as they reduce the risk of air aspiration.

Rarely, the right subclavian vein is used when patient’s anatomic factors make the internal jugular and femoral veins inappropriate for access.¹⁶ The entry site into the subclavian vein should be somewhat more lateral than is routinely the case for subclavian venous catheterization, as too acute a superior vena cava/subclavian vein angle will prevent the relatively stiff bioptome from negotiating this angle into the right heart. The standard site of entry for subsequent heart biopsy is the infraclavicular region, lateral to the area of the bend of the clavicle. The preceding recommendations regarding anesthesia application and vein entry apply in this case as well. The needle is directed medially in a plane virtually parallel to the surface of the x-ray table toward the region of the supraclavicular notch. If this is unsuccessful, approaches more inferior or at a steeper angle to the chest wall can be attempted. The standard single-wall or micropuncture technique is used, as noted above. All intravascular catheters should move without obstruction. In both the internal jugular and subclavian techniques, fluoroscopy should be used to ensure that the guidewire is directed downward toward the inferior vena cava or right atrium rather than upward toward the head.

Although entry into the femoral vein is technically less challenging, biopsy from the femoral vein is more difficult. In a series of biopsy patients reported by Anderson and Marshall,¹⁷ the internal jugular vein could not be cannulated in 12% of patients, whereas all had successful femoral vein insertion. The femoral vein is located just medial to the femoral artery, and the site of entry should be inferior to the inguinal ligament. The femoral artery can serve as a constant landmark for orientation. The Amplatz, Seldinger, or micropuncture techniques are all used for the femoral venous approach. Ultimately, a guiding sheath of variable length is inserted in the inferior vena cava from the femoral venous site.

The femoral artery is approached in a fashion very similar to the approach adopted for the femoral vein. Left ventricular biopsies are occasionally indicated in patients with specific left ventricular masses or local pathology, isolated ventricular dysfunction, or an infiltrative process specific to the left ventricle.¹⁸ The risks of embolization and perforation are somewhat higher for patients submitted to left ventricular endomyocardial biopsy as evidenced by higher incidence of pain, low blood pressure, and pericardial effusions after left, as opposed to right, ventricular endomyocardial biopsy. After femoral sheath insertion, a constant infusion drip should be maintained through the sheath to avoid clot formation within the lengthy catheters and air embolization.

The preshaped 50-cm bioptome is inserted through the venous sheath with the tip of the bioptome pointing toward the anterior wall of the right atrium. In the mid-right atrium, the bioptome is advanced slowly as it is turned counterclockwise. This is facilitated by the fact that the direction of the bioptome head is concordant with that of the handle; nevertheless, free motion and the desired orientation should always be confirmed fluoroscopically. The anterior rotation of the bioptome head allows the tip to cross the tricuspid valve while it avoids the coronary sinus and tricuspid apparatus. Continued advancement and counterclockwise rotation then allow the bioptome to advance farther into the right ventricle and orient toward the septum (Figure 26.7). Extreme care must be exercised during this maneuver to avoid perforation of the vena cava, right atrium, or right ventricular free wall by the relatively stiff bioptome. If resistance is encountered, the bioptome should be pulled back and a different angle of entry attempted—the biopsy forceps should never be forced or prolapsed into the ventricle. If entry into the right ventricle remains difficult, a Swan-Ganz catheter or other balloon flotation device may be used to define the pathway across the tricuspid valve into the right ventricle.

Once in the right ventricle, the bioptome should lie against the midportion of the interventricular septum. On fluoroscopy, the bioptome should lie across the patient’s spine and is usually directed inferiorly below the plane of the tricuspid valve. If there is any question as to the bioptome’s position, fluoroscopy in the 30° right anterior oblique (RAO) and 60° left anterior oblique (LAO) projections will confirm whether the catheter is on the ventricular side of the atrioventricular groove and pointed toward the septum. The correct position is also marked by ventricular ectopy; absence of such ectopy and fluoroscopy showing the catheter as lying in the atrioventricular groove suggest that the bioptome has entered the coronary sinus or the infradiaphragmatic venous system. It must be withdrawn and repositioned before the jaws are opened and an attempt is made to retrieve tissue.

Even within the right ventricle, it is important to avoid the relatively thin right ventricular free wall (Figure 26.8) by directing the head of the biopsy forceps toward the interventricular septum. The interventricular septum lies in a plane approximately 45° diagonal to the plane of the patient’s chest wall and corresponds to orientation of the instrument handle leftward and posteriorly. In patients with cardiomyopathy, especially those with elevated pulmonary pressure or right ventricular enlargement, the orientation of the handle may be straight posterior.

Contact with the interventricular septum is confirmed by the appearance of premature ventricular contractions. The biopsy forceps are then withdrawn 1 to 2 cm, opened, and advanced slowly to engage the septum. The biopsy head is slowly closed to encapsulate the endomyocardial specimen. Because of the trabeculated nature of the endomyocardial surface, gentle forward pressure should be maintained while the jaws are being closed, to ensure myocardial contact. Patients with restrictive heart disease or following transplant often demonstrate a pulsatile transmission of ventricular contractility through the course of the bioptome, whereas those with idiopathic dilated cardiomyopathy are often “soft” and engagement of the ventricular septum is confirmed only by premature ventricular contractions.

After the biopsy has been secured, the operator must maintain pressure on the forceps closure device to make sure the jaws remain closed while the specimen is withdrawn from the right ventricle, right atrium, and superior vena cava. There may be some slight “give” as the specimen is released from the myocardium. Specimens that require excessive force to remove suggest entrapment of the tricuspid apparatus, transmural biopsy, or biopsy of a scar focus. In these circumstances, the bioptome head is released by opening the jaws, the bioptome is withdrawn, and another biopsy site selected. Once removed, the specimen must be scooped from the forceps and placed in an appropriate preservative.

Patients not infrequently experience a pulling or tugging sensation as the specimen is withdrawn from the heart surface. Sharp chest pain during bioptome insertion or during the performance of an endomyocardial biopsy implies cardiac perforation. Other clues to possible perforation include persistent premature ventricular contractions, excessive retraction of the ventricular wall during biopsy withdrawal, and a biopsy specimen that floats in formalin (suggesting epicardial fat content). Any of these markers should prompt blood pressure checks and fluoroscopy of the heart borders to detect signs of pericardial tamponade. This risk is lowest in patients with prior cardiac surgery or advanced cardiomyopathy and highest in nonsurgical patients with relatively normal chamber size and systolic function.

Patients with heart transplantation who undergo repeated heart biopsies may require variation in the direction of the biopsy forceps to avoid scarred areas of prior biopsy. This may include some anterior or posterior angulation or alteration of the degree of curvature in the bioptome. The number of specimens taken per biopsy procedure is variable and dependents on the patient’s clinical status. The operator must balance the pathologist’s desire to have adequate tissue and the risks involved with performance of the procedure. We usually take three to five samples to yield adequate tissue for examination and to detect focal pathology that might not be evident in a single sample.

At the conclusion of the procedure, the heart border should be examined fluoroscopically to exclude tamponade before the venous sheath is removed and the puncture site is dressed. Patients who have had serial biopsies (e.g., transplant patients) can be discharged home within 10 minutes of uncomplicated biopsy.

The disposable preformed sheath technique can also be used from the internal jugular approach. It differs from the preformed bioptome technique as described above in that the sheath (rather than the bioptome itself) is advanced into the right ventricle. This directs the bioptome, which is very flexible and lacking in inherent shape. A 7-French 45-cm preformed sheath can be inserted into the superior vena cava and right atrium through a short 9-French self-sealing sheath. Insertion of a smaller sheath through a larger sheath allows better torque control and decreases the risk of biopsy sheath kinking. The preformed sheath is guided into the right ventricle by use of a guidewire or a balloon-tipped flotation catheter. Once the sheath is in the right ventricle, the catheter or wire guide is removed while the sheath remains in position. If there is any question as to the right ventricular placement, the side arm of the guiding sheath can be attached to a pressure
monitor and right ventricular pressure demonstrated, or a gentle contrast injection can be performed. The tip of the preformed sheath should be free floating rather than positioned against the ventricular myocardium or trabeculated portion of the right ventricle muscle. Once in a stable position, the sheath should be aspirated and flushed with heparinized solution. The sheath should be connected to a constant-infusion port to maintain patency and avoid clot formation.

The flexible biopsy catheter is then inserted through the disposable sheath. The distal portion of the biopsy forceps can be manually curved before entry into the sheath to avoid straightening of the sheath during insertion of the bioptome and thus disturbing the appropriate angle for biopsy performance. The jaws of the bioptome should be opened immediately on exiting the sheath to increase cross-sectional area and thereby reduce the risk of perforating the myocardial wall. The bioptome is directed posteriorly and perpendicular to the plane of the septum. Gentle pressure is applied as the jaws are slowly closed. Once the bioptome has been removed from the sheath, the jaws are opened and the specimen removed. The bioptome jaws are flushed with saline, and repeated biopsies are taken as indicated clinically. Repeated biopsy attempts may require alteration in the direction of the sheath or angulation of the bioptome.

This technique differs from the right internal jugular approach in the type of sheath used. After the 6-French 10-cm sheath is introduced in the left internal vein in the regular fashion, the sheath is exchanged over a 0.035-inch wire for a 6-French flexible-destination 45-cm sheath. Under careful fluoroscopy guidance, the 45-cm sheath is placed in the right atrium, the wire is removed, and then the bioptome is advanced into the right ventricle.

As with the right internal jugular venous approach, we prefer to insert a 9-French self-sealing sheath in the femoral vein through which a 7-French guiding sheath is inserted. All guiding sheaths have an angle of curvature, which varies from a 135° straight angle to a gentle 180° curvature or multiangulated curvature²² (Baim guiding sheath). Each of these types is inserted into the right ventricular cavity with the assistance of an internal dilator, wire guide, pigtail catheter, or flotation balloon-tipped catheter. Rarely, the femoral venous approach is used to biopsy the left ventricle in children via a transseptal approach.²³ The femoral approach allows the operator less control over the site and location of the endomyocardial biopsy, which may increase the risk for perforation.

The 130°-angle femoral sheath must be evaluated before insertion to ensure that the length of the sheath extension from the right atrium to right ventricular biopsy site does not exceed the anatomic distance from the right atrial border to the right ventricular apex. This can be done by placing the sheath on the exterior portion of the patient’s chest under fluoroscopy. If the postangled portion of the bioptome is too long, it should be shortened before insertion.

As with the internal jugular approach using a preformed sheath, insertion of the bioptome may straighten the sheath, altering the ideal angle for performance of the biopsy. If this is the case, the distal portion of the otherwise unformed 104-cm bioptome can be manually preshaped before insertion, into a curve similar to that of the sheath to decrease the chance of losing the ideal biopsy angle. Out-of-plane posterior angulation of the tip of the bioptome relative to the broad, more proximal curve can help direct the tip toward the ventricular septum as it exits the sheath.

Once the preformed sheath is inserted, it should be continuously flushed to avoid clot formation, thromboembolic complications, and air embolism. If there is a question as to the biopsy sheath tip location, a hand flush of contrast dye may be helpful (Figure 26.9). The 104-cm bioptome is inserted through the disposable sheath. The biopsy jaws should be opened just as the bioptome exits the preformed sheath, decreasing the potential for perforation by the bioptome. The biopsy forceps are advanced to the myocardial border with the jaws open. The jaws are slowly closed while gentle pressure is maintained against the septum. If the tip of the preformed sheath lies against the septum, the biopsy forceps can be unsheathed by retracting the sheath while maintaining the biopsy forceps in a stable position. This decreases the potential for perforation. After the specimen is obtained, as the biopsy forceps are withdrawn, the sheath is advanced slightly to restore its original position in the ventricle. Once the biopsy specimen has been removed from the preformed sheath, the forceps are opened and the specimen scooped from the jaws and placed in an appropriate preservative.

As with the femoral venous approach, the femoral artery approach requires insertion of a larger preformed short sheath to maintain artery patency and allow biopsy sheath manipulation. Both the short and the long (98-cm) femoral artery disposable sheaths must be maintained under constant pressurized infusion with a heparinized solution to maintain patency and avoid embolic phenomenon. The preformed sheath is inserted into the left ventricular cavity using a guidewire and a pigtail catheter. The wire, pigtail catheter, and preformed sheath are gently manipulated to cross the aortic valve and enter the left ventricular cavity. Once in the left ventricle, an area of acceptable irritability is established. The inferior posterior portions of the left ventricular cavity as well as areas of previous myocardial infarction should be avoided to reduce the risk of perforation because of the relatively thin muscle in these sites.

The sheath is cleared of debris by aspirating and flushing before the 104-cm bioptome is inserted through the sheath and into the left ventricular cavity. The biopsy forceps should be directed away from the mitral valve apparatus. The jaws are opened and directed to the left ventricular wall, the specimen is encapsulated, and the jaws are closed firmly with extraction of the sample. Because of the increased contraction of the left ventricle, less forward pressure is applied while performing the biopsy. The sheath is maintained in the left ventricular cavity and its position adjusted to ensure sampling from several sites.

A retrograde left ventricular biopsy can also be performed using a 7-French JR4 guiding catheter which is passed through the aortic valve into the left ventricle using a standard J-tip guide wire. To reach the inferior, posterior, lateral, and apical walls the JR4 guiding catheter is the best option. For the anterior segments the recommended guiding catheter is the AL1, and for the left ventricular septum, the JL4. The disposable 105-cm bioptome is advanced through the guiding catheter into the left ventricle under biplane-fluoroscopic or echocardiographic guidance.

Another option, instead of using the guiding catheter, is to use a 7F-long guiding sheath with a straight tip.

After each biopsy, aspiration of blood from the guiding catheter and rinsing with heparinized sodium chloride are performed to prevent clotting.²⁴ Anticoagulation with heparin during the procedure (target ACT 150 second) has also been recommended.²⁴

The greatest risk to patients from the performance of endomyocardial biopsy is ventricular perforation,³⁰ which may result in pericardial tamponade and potential death. Patients with an International Normalized Ratio (INR) of >1.5 or who have received heparin without reversal within the preceding 2 hours should probably not be submitted to endomyocardial biopsy. Perforation is usually a complication of
injury to the right ventricular free wall, which is only 1 to 2 mm thick. Patients with pulmonary hypertension, a bleeding diathesis, or right ventricular enlargement may be at increased risk for right ventricular perforation. Any patient complaining of sharp pain during the performance of the endomyocardial biopsy should be considered to have experienced cardiac perforation. Patients in whom perforation occurs immediately complain of a visceral pain and within 1 to 2 minutes may develop bradycardia and hypotension. This is in part owing to an exaggerated vagal response, but limited benefit is achieved by atropine administration. No further biopsy attempts should be made until the significance of the patient’s complaints has been fully investigated. This may include fluoroscopy of the heart border, measurement of the right atrial pressure waveform, or performance of a portable echocardiogram. Patients with suspected perforation should have their right atrial pressure and the pulsatility of the right and left heart borders continuously monitored. Loss of pulsation of heart borders and increased right atrial pressure are strong indicators for pericardial tamponade. Echocardiography should be obtained immediately to determine the presence and severity of pericardial blood accumulation, and it is our preferred method for assessing and monitoring patients with suspected perforation. Cardiovascular collapse or electrical-mechanical disassociation in the setting of a biopsy should be considered to be presumptive evidence of pericardial tamponade, and the operator must be prepared to do an immediate pericardiocentesis, even before echocardiographic confirmation of tamponade.