Either ultrasound guidance or non-contrast enhanced, CT guidance can be used for splenic biopsy. The imaging modality that best demonstrates the lesion within the spleen should be selected. The advantage of ultrasound guidance is that it provides real-time imaging in multiple planes and visualization of the needle during biopsy (Fig. 15.2). An advantage of CT guidance is the ability to accurately visualize adjacent organs, such as the colon, lung, and kidney, and their anatomic relationships to the spleen (Fig. 15.3). In some cases, the lesion cannot be seen with non-contrast-enhanced CT and the administration of intravenous contrast may be necessary for lesion localization. Another advantage of CT guidance is that a non-contrast-enhanced CT scan can be obtained immediately after the procedure to evaluate for potential complications, such as pneumothorax and hemorrhage.

Fine-needle aspiration of the spleen is usually performed using 20- to 22-gauge needles [3, 4, 7, 16]. Core-needle biopsies using 18- to 20-gauge needles have also been reported [17]. Biopsy with larger gauge needles (e.g., 14-gauge needles) has been reported, but the use of these larger needles is associated with an increased risk of hemorrhage [18].

In contrast to liver biopsy, for which a biopsy tract through normal liver tissue is recommended to provide a tamponade effect, splenic biopsy should be performed on the most peripherally located lesion, thereby traversing the least amount of splenic tissue and minimizing the potential for hemorrhagic complications. The patient should be positioned so that the most direct path for biopsy of the lesion is accessible. Typically, when biopsy is performed under ultrasound guidance, the patient is in a supine or right lateral decubitus position [9, 17]. Several authors recommend that the patient be instructed to suspend respiration during needle insertion and biopsy to minimize needle movement and the resulting trauma to the splenic tissue [2, 8, 9, 19]. A subcostal approach is favored, although an intercostal approach may be necessary depending on the lesion’s location. For splenic lesions in the upper pole, the triangulation method or angling of the CT gantry may be necessary to avoid traversal of the pleural reflection [20]. Most ultrasound-guided biopsies are performed using a free-hand technique, as most lesions are located in the periphery of the spleen [4]. For deeper lesions, a coaxial technique may be helpful and allows for both fine-needle aspiration and core biopsy to be performed with only one puncture of the spleen.

Splenic biopsies can be performed on an outpatient basis. Following the procedure, patients should be observed for potential complications. Postprocedural observation times vary between 2 and 4 h [9, 11, 19] and include monitoring of the patient’s blood pressure, pulse, and oxygen saturation. Postprocedural chest radiography should be performed in patients in whom a pleural surface was traversed to evaluate for pneumothorax. Patients who remain stable following the observation period, with minimal or no discomfort, can be discharged home. Patients should be instructed to avoid heavy lifting and strenuous activity for at least 3 days, as delayed hemorrhagic complications have been reported [4, 11, 18, 19].

In 1976, Soderstrom reported no complications in a series of more than 1,000 “blind” splenic biopsies [2]. More recently, complication rates ranging from zero to 16.7 % have been reported for splenic biopsy (Table 15.1). Unfortunately, uniform criteria for reporting complications have not been applied across the studies, making direct comparisons difficult. Most postbiopsy complications are minor and self-limited, requiring no additional treatment. For example, postprocedural pain occurring in the left upper quadrant or radiating to the left shoulder has been described in up to 50 % of patients after percutaneous splenic biopsy [18]. Hemorrhage following splenic biopsy has been reported in zero to 8.3 % of patients [3, 5, 11, 16, 17, 21]. Most cases of hemorrhage are self-limited, perisplenic hematomas that do not require further intervention (Fig. 15.4); however, although rare, uncontrolled hemorrhage has been reported and can result in the need for blood transfusions, the need for emergent splenectomy, or death[1, 11, 16] (Fig. 15.5). Other complications such as pneumothorax, pleural effusion, and colonic injury have also been described [3, 5].