13 Interventional Radiology of the Spleen H. VEREYCKEN, R. V AN HEE, E. TOTTE and L. HENDRICKX
13.1 Introduction 141 13.2 Percutaneous Biopsy of the Splenic
Parenchyma 141 13.3 Endovascular Embolization as a Sole Treatment in
the Splenic Trauma Patient 142 13.4 Embolization of the Spleen as a Treatment of
Hypersplenism 143 13.5 Embolization of the Spleen as a Preoperative Measure
in Laparoscopic Splenectomy 143 13.6 Conclusions 145
Interventional radiological techniques have been used increasingly in the management of splenic disorders during recent decades. This attitude went along with a more conservative approach that sur-geons and traumatologists adopted in dealing with splenic trauma and hypersplenism. When it be-came obvious that a correlation existed between splenectomy and increased risk for life-threatening sepsis (Pneumococcus, Hemophilus influenza, Men-ingococcus, Staphylococcus aureus, Streptococcus and Pseudomonas), especially in children and ado-lescents, a progressive shift was noted from an ag-gressive and resectional type of management to a more conservative, possibly spleen-saving therapy (GRECO and ALVAREZ 1981). Moreover, greater un-derstanding has been reached concerning not only the immunological role of the spleen and its diseases, but also the definition and classification of hyper-splenic syndromes, thereby reducing the number of splenectomies performed for such syndromes (KING and SCHUMACKER 1952; O'NEAL and McDONALD 1981; GREEN et al. 1986; PICKHARDT et al. 1989; VAN HEE 1997).
H. VEREYCKEN, R. VAN HEE, E. TOTTE, L. HENDRICKX; De-partment of Radiology, Academic Surgical Center, Stuivenberg, Lange Beeldekensstraat 267, B-2060 Antwerp, Belgium
There are many interventional radiological proce-dures. Percutaneous biopsy of splenic lesions is per-formed for cytological or histological diagnosis but still carries a substantial morbidity that is directly related to the technique. Indications for biopsy are also limited due to more performant and less dan-gerous alternatives in medical imaging and diagno-sis. Accidental puncture of the spleen during biopsy or during drainage of abdominal processes may occur and should be considered a severe complica-tion that needs careful follow-up. Splenic abscesses may be drained successfully using a percutaneous approach. Embolization of the splenic artery in trauma aims to achieve a quick peripheral occlusion of the lacerated vessel in these often critically ill patients. Peripheral embolization as the sole treatment in hypersplenism may be performed in selected patients but has an important complication rate. Combined peripheral and main splenic-artery embolization, as a procedure before laparoscopic splenectomy, yields favorable results by decreasing perioperative complications and increasing the com-fort and ease of the surgeons.
13.2 Percutaneous Biopsy of the Splenic Parenchyma
Percutaneous puncture of the spleen has been pro-posed, for diagnostic purposes, in cases ofhematol-ogical or oncological disorders. Recently, O'MALLEY et al. (1999) defined the indications for percutaneous biopsy of the spleen:
1. The presence of a single lesion or multiple lesions without characteristics on medical imaging in a patient without known primary tumor and with a normal immune status
2. The presence of a splenic mass in a patient with a known primary malignancy
3. More rarely, the presence of a splenic lesion in an immunocompromised patient for whom the re-
A. M. Schepper et al. (eds.), Medical Imaging of the Spleen Springer-Verlag Berlin Heidelberg 2000
sults of clinical, imaging and blood culture find-ings are inconclusive
Preparation for the procedure consists of coagula-tion studies, a conscious sedation, an intravenous line and informed consent. The risk of bleeding must be minimized by identifying an underlying coagulopathy (prothrombin time, partial thrombo-plastin time and platelet count), avoiding biopsy of hilar lesions, using 20- to 22-gauge needles, having a cytopathologist who can limit the number of passes in the examination room, performing the procedure under ultrasound (US) guidance instead of com-puted tomography (CT) and embolizing the needle track with autologous blood cloths or gelfoam par-ticles. Monitoring of vital functions during and after the procedure and follow-up after discharge will decrease the morbidity rate of splenic aspiration biopsies.
Accidental puncture of the spleen during US- or CT -guided diagnostic or therapeutic percutaneous maneuvers may occur. Bleeding often results. Care-ful intensive care observation with regular clinical and US controls is mandatory to evaluate intra-abdominal bleeding or hematoma formation that may need surgical intervention.
Percutaneous drainage of splenic abscesses has been performed successfully in many instances. The same precautions as for percutaneous biopsy are taken. A trocar or Seldinger technique can be used with a success rate of 70-80%. The splenic abscess is evacuated via an anterolateral of posterolateral approach, and antibiotic therapy is administered. Post-puncture pleural effusion may occur (BERKMAN et al. 1983; QUINN et al. 1986).
13.3 Endovascular Embolization as a Sole Treatment in the Splenic Trauma Patient
In view of the spleen's well-documented importance in the immune response of the body, surgeons in-creasingly tend to treat splenic trauma in a conserva-tive, non surgical-manner if possible (KREUZFELDER et al. 1991). Adequate clinical, biological and radiological examinations are mandatory to select patients for conservative treatment (TRAUB and PERRY 1981; BUNTAIN et al. 1988). Angiography, particularly with embolization, should not be per-formed without careful monitoring the general con-dition of a potentially instable patient. Therefore, some prerequisites for treatment by embolization
H. Vereycken et al.
should be taken into account (GETRAJDMAN and SCLAFANI 1997). 1. The patient must be hemodynamically stable
without signs of hollow viscus perforation. 2. A CT scan should demonstrate non-splenic le-
sions that may need urgent operation or require immediate treatment; in such a case, a careful balance of priorities must be made and may turn in favor of immediate surgery.
3. In smaller hospitals, especially at night, the un-availability of an experienced interventional radi-ologist may preclude an embolization procedure.
However, coagulopathy may be only a relative contraindication, since a vascular sheath can be left in place until the coagulopathy is corrected. Taking the cited prerequisites into account, the ultimate goal may also be to save the patient's splenic parenchyma.
Concerning the embolization technique, a celiac trunk angiography is initially performed not only to detect possible additional lesions but to obtain a complete anatomical cartography. Subsequently, selective catheterization of the splenic artery is performed at a point distal to the dorsal pancreatic artery, an important collateral-supply artery. Diag-nostic angiography in one or two incidences is then obtained. If no extravasation is seen, the procedure is ended. Some teams perform another series after intra-arterial vasodilatation (with tolazoline) to overcome false-negative results due to vasospasm.
In cases of extravasation, selective catheterization and embolization of the artery is obtained with relatively large hand-cut gelfoam particles, to which a small coil may be added. If this "superselective" embolization cannot be achieved within a reasonable time span and using a reasonable amount of contrast medium, the distal splenic artery is embolized just before the hilus with one or more bigger (5-8mm) coils. Generally, a complete embolization may be achieved. Even when extravasation is not completely stopped, the procedure (in most instances) results in clinical success. Extra care is given to sterility during the whole procedure. Preventive antibiotics are generally administered, which virtually annihilates infectious complications. As already mentioned, no embolization is performed if there is no active extravasation. A patchy "starry-night" appearance of the spleen is not considered an extravasation and is not treated by embolization (Chap. 8 Fig. 8.12). If, at the end of the procedure, a tolerable contrast dose has not been exceeded, a control angiography of the
Interventional Radiology of the Spleen
celiac trunk is performed to illustrate collateral vas-cular supply to the spleen.
The patient is generally kept in an intensive care unit for a couple of days; in most cases, if his/her general condition permits, he/she can be discharged after 1 week following a control CT scan (DONDELINGER and KURDZIEL 1990; GETRAJDMAN and SCLAFANI 1997). The spleen normally has an excellent capacity to regenerate, so up to 80% of the parenchyma may be sacrificed without jeopardizing immunological function.
Results of splenic embolization for trauma have been very rewarding. More than 95% of patients with arterial extravasation may be managed conserva-tively and do not re-bleed or require operation. Combining CT scan, peritoneal lavage and angio-graphy with arterial-splenic embolization allowed SCLAFANI et al. (l991) to non-operatively manage a great number of patients with splenic trauma with success.
13.4. Embolization of the Spleen as a Treatment of Hypersplenism
Hypersplenism is a condition occurring in several diseases and is characterized by severe pancyto-penia, splenomegaly and reactive, hyperplastic bone marrow. The term hypersplenism was first used by Chauffard in 1907. There are primary and secondary forms of hypersplenism. The primary form consists of depression of one or more of the blood cell lines. This form is associated with clear-cut splenomegaly and is successfully treated by splenectomy (SCHWARTZ et al. 1971). Secondary hypersplenism refers to a condition of pancytopenia that is associated with either portal hypertension of intra-or extrahepatic origin, or splenic-vein obstruction. In contrast to hepatically induced portal hyper-tension, splenic-vein obstruction (characterized by gastric variceal bleeding) responds well to splenectomy.
To avoid a surgical intervention and its complica-tions, radiological catheter embolization of the spleen has been proposed. Initial failures included frequent abscess formation, splenic rupture, sepsis and pneumonia. Antibioprophylaxis and repeated treatment, with occlusion of different arterial branches at each session, have improved the final outcome (PAPADIMITRIOU et al. 1976; WHOLEY et al. 1978; SPIGOS et al. 1979). Splenic artery embolization represents a most attractive alternative option, espe-
cially in patients with hypersplenism after renal transplantation or due to immunosuppressive dis-eases (GERLOCK et al. 1982).
The technique of embolization is essentially the same as the one used in trauma patients. However, in patients with hypersplenism, the procedure is frequently divided into different sessions to avoid major complications (DONDELINGER and KURDZIEL 1990).
Data published between 1975 and 1985 reported an overall complication rate of 18%, with a mortality rate of 7.5% (O'NEAL and McDoNALD 1981). However, dividing the series into two 5-year time periods shows a significant reduction in com-plications and mortality rate. In particular, the complication rate was reduced by following the multistage protocol advocated by SPIGOS et al. (l980) or by limited peripheral embolization, as proposed by DELCOUR et al. (l982). Minor com-plications may still occur and include left upper-quadrant abdominal pain, fever, paralytic ileus with nausea and vomiting and pleural effusions (KuMPE et al. 1985). Nevertheless, even with the use of these protocols, embolization in patients with hypersplenism remains hazardous, and careful selection of patients should be considered.
13.5 Embolization of the Spleen as a Preoperative Measure in Laparoscopic Splenectomy
Splenic-artery embolization as a preoperative ad-junct to laparoscopic splenectomy was first de-scribed by POULIN et al. (l993) in an attempt to reduce intraoperative bleeding during the laparoscopic procedure. Indeed, bleeding frequently occurred in early cases oflaparoscopic splenectomy, when the operation was performed by means of an anterior approach (CARROL et al. 1992; DELAITRE and MAIGNIEN 1992; LEFOR et al. 1993; POULIN et al. 1993; FLOWERS et al. 1996). Later laparoscopic splenectomy has mostly been performed by means of a lateral approach, the so called hanging-spleen technique introduced by DELAITRE (l995). This operative technique allows an easy dissection of the avascular retrosplenic plane, starting at the lower pole attachments with the colon and going up to the phrenicosplenic ligament (TRIAS et al. 1996). Even with this lateral approach, anterior splenic-dissection bleeding may occur from small gastric vessels, the splenic capsule or the parenchyma dur-
ing lifting of the spleen with laparoscopic instru-ments (TOTTi et al. 1988; MITCHELL et al. 1993; POULIN et al. 1993).
To manage these hemorrhagic events, pre-operative arterial embolization of the spleen has been proposed. The technique is identical to the one used in cases of post-traumatic splenic rupture. After embolization of the splenic parenchyma with large hand-cut gelfoam particles, the procedure is ended with the introduction of one or two coils (5-8mm) distal to the dorsal pancreatic artery. If ana-tomical variations are present, the embolization technique is adapted to the radiological findings, and additional catheterization and selective embo-lization of polar arteries may be performed (Figs. 13.1, 13.2).
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Indications for laparoscopic splenectomy include various hematological disorders, such as immune thrombocytopenic purpura, autoimmune hemolytic anemia, hereditary spherocytosis and, to a lesser extent, non-Hodgkin lymphoma. In the reported series, the results of preoperative embolization tech-niques have been excellent, especially in moderately sized spleens not exceeding 20 cm in length. These results are shown in Table 1.
In larger spleens (>20cm), POULIN et al. (1998) found a higher frequency of blood loss despite of preoperative embolization of the spleen. As shown in Table 2, this was not confirmed in the series of TOTTi et al. (1988). Complications in both series included a case of mild pancreatitis not inducing clinical symptoms and occurring in one of 26
Fig. 13.1. Embolization of the splenic artery. a Angiography of the splenic artery before embolization. b Superselective catheterization of the splenic artery. c Angiography of the splenic artery after embolization, with sparing of the pancreatica magna artery
Interventional Radiology of the Spleen
Fig. 13.2. Laparoscopic view of the spleen 24h after emboliza-tion of the splenic artery. The spleen is enlarged and has a blueish dis...