Splenic arterial interventions: anatomy, indications, technical considerations, and potential complications

[Laparoscopic splenectomy: indications, techniques, outcomes]

Laparoscopic splenectomy (LS) has become the standard approach to splenectomy for benign and malignant hematologic diseases despite a paucity of high-level evidence. The procedure requires expertise in laparoscopic surgical techniques and meticulous dissection of the spleen. Management should include a preoperative radiologic assessment to measure splenic volume and to detect the presence of accessory splenic tissue; the patient should undergo preoperative vaccination against meningococcal, pneumococcal, and Haemophilus influenzae type B infections. Prophylactic antibiotics are used in the perioperative period as well as prophylactic anticoagulation therapy which may be continued long-term in high-risk patients. LS is associated with a low morbidity and mortality; when compared to laparotomy, it reduces the length of hospital stay and improves the quality of life by decreasing postoperative ileus and pain. There are a variety of laparoscopic approaches; the hand-assisted technique and newer coagulating devices have facilitated the operative technique leading to increasing acceptance of laparoscopy as the preferred approach - even in patients with malignant hematologic disease and/or massive splenomegaly.

Interventional radiology for paediatric trauma

Paediatric interventional radiology plays a cornerstone role in the management of paediatric trauma. In the acute setting, interventional radiology techniques allow minimally invasive control of haemorrhage or re-establishment of blood flow. Percutaneous stenting and drainage can allow disruptions in urinary or biliary systems to heal without the need for further surgery. Interventional radiology techniques also have a significant role in treating delayed complications of trauma, including embolization of arterial pseudoaneurysms and pulmonary embolism prophylaxis in individuals immobilized due to the trauma or its operative treatment.

Role of imaging in the management of splenic artery steal syndrome

OBJECTIVE

The purpose of this study is to discuss the etiology and role of imaging in the management of splenic artery steal syndrome (SASS) following orthotropic liver transplantation (OLT).

METHODS

Hepatic arterial thrombosis and stenosis have been the most commonly recognized arterial complications following OLT. Splenic artery steal syndrome is a recently described entity in the transplant literature and thought to be an under-recognized cause of graft ischemia. It is characterized by hepatic arterial hypoperfusion accompanied by splenic arterial and portal venous hyperperfusion and leads to various vascular and biliary graft complications. Because the clinical manifestations of SASS are so non-specific, imaging plays a key role in the diagnosis of this condition.

RESULTS

This article discusses the role of imaging in the management of this potentially reversible cause of graft ischemia.

CONCLUSIONS

Awareness of the imaging features and having a high index of suspicion are essential for the early diagnosis and prompt management of this condition.

Effect of catheter-directed arterial embolization and laparoscopic endovascular stapling on stapled vessel integrity in a porcine model

Arterial embolization is a frequently performed adjunctive maneuver prior to laparoscopic splenectomy or nephrectomy to facilitate laparoscopic dissection and reduce intraoperative bleeding. However, little is known regarding the effect of laparoscopic stapling across thrombosed vessels with imbedded embolic materials. This study analyzed the stapled line integrity by comparing visceral arteries treated with either platinum coils or polyvinyl alcohol (PVA) particles. Using a porcine model, 30 visceral vessels including splenic and renal arteries were treated with either coil or PVA embolization, which was followed by laparoscopic stapling. Vessel integrity and bursting pressure analysis was performed using an in vitro flow circuitry. The mean bursting pressure of the coil and the PVA group was 158 +/- 56 and 350 +/- 34 mm Hg, respectively (p < .001). The lowest bursting pressure in the coil and the PVA group was 70 and 280 mm Hg, respectively. The highest bursting pressure in the coil and the PVA group was 225 and 420 mm Hg, respectively. The bursting pressure in the splenic artery between the PVA and the coil group was 345 +/- 29 and 150 +/- 54 mm Hg, respectively (p < .001). Significant difference in the bursting pressure in the renal artery was noted in the PVA and the coil group, which was 350 +/- 40 and 160 +/- 40 mm Hg, respectively (p < .001). Our findings showed that preoperative coil embolization followed by laparoscopic vessel stapling sustained a poor busting pressure. Such a practice appears to be unsafe based on our findings and should be performed with caution in a clinical setting.

Splenic Artery Embolization and Endovascular Stapler Integrity in a Porcine Model

Splenic artery embolization is often used before laparoscopic splenectomy in cases of splenomegaly to reduce blood loss and facilitate the procedure. The aim of this study was to examine the general reliability of endovascular staplers when fired at the site of embolization coil deployment using a porcine model. Ex vivo and in vivo experiments were conducted on porcine abdominal aortas, which are similar in diameter to those of the splenic artery in the human. When the endovascular staplers were fired across the porcine vessels at the area of embolization coil deployment ex vivo, the staple lines all failed. In contrast, in vivo, the staple lines remained intact with no bleeding despite resistance imposed by the intravascular coils. Despite consistent failure in the ex vivo studies, in vivo all staple lines held and permitted safe transection of the vessel. We presume that the hemostatic properties of the coils caused sufficient thrombosis in this model, which mimics the clinical situation, to permit division of the previously embolized splenic vessel.

Partial splenic embolization

Partial splenic embolization (PSE) is a non-surgical procedure developed to treat hypersplenism as a result of hepatic disease and thus avoid the disadvantages of splenectomy. A femoral artery approach is used for selective catheterization of the splenic artery. Generally, the catheter tip is placed as distally as possible in an intrasplenic artery. After an injection of antibiotics and steroids, embolization is achieved by injecting 2-mm gelatin sponge cubes suspended in a saline solution containing antibiotics. PSE can benefit patients with thrombocytopenia, esophagogastric varices, portal hypertensive gastropathy, encephalopathy, liver dysfunction, splenic aneurysm, and splenic trauma. The contraindications of PSE include secondary splenomegaly and hypersplenism in patients with terminal-stage underlying disease; pyrexia or severe infections are associated with a high risk of splenic abscess after PSE. Complications of PSE include daily intermittent fever, abdominal pain, nausea and vomiting, abdominal fullness, appetite loss, and postembolization syndrome. Decreased portal-vein flow and a rapid increase in the platelet count after excessive embolization may cause portal-vein or splenic-vein thrombosis.

Laparoscopic splenectomy: the clinical practice guidelines of the European Association for Endoscopic Surgery (EAES)

BACKGROUND

Although laparoscopic splenectomy (LS) has become the standard approach for most splenectomy cases, some areas still remain controversial. To date, the indications that preclude laparoscopic splenectomy are not clearly defined. In view of this, the European Association for Endoscopic Surgery (EAES) has developed clinical practice guidelines for LS.

METHODS

An international expert panel was invited to appraise the current literature and to develop evidence-based recommendations. A consensus development conference using a nominal group process convened in May 2007. Its recommendations were presented at the annual EAES congress in Athens, Greece, on 5 July 2007 for discussion and further input. After a further Delphi process between the experts, the final recommendations were agreed upon.

RESULTS

Laparoscopic splenectomy is indicated for most benign and malignant hematologic diseases independently of the patient's age and body weight. Preoperative investigation is recommended for obtaining information on spleen size and volume as well as the presence of accessory splenic tissue. Preoperative vaccination against meningococcal, pneumococcal, and Haemophilus influenzae type B infections is recommended in elective cases. Perioperative anticoagulant prophylaxis with subcutaneous heparin should be administered to all patients and prolonged anticoagulant prophylaxis to high-risk patients. The choice of approach (supine [anterior], semilateral or lateral) is left to the surgeon's preference and concomitant conditions. In cases of massive splenomegaly, the hand-assisted technique should be considered to avoid conversion to open surgery and to reduce complication rates. The expert panel still considered portal hypertension and major medical comorbidities as contraindications to LS.

CONCLUSION

Despite a lack of level 1 evidence, LS is a safe and advantageous procedure in experienced hands that has displaced open surgery for almost all indications. To support the clinical evidence, further randomized controlled trials on different issues are mandatory.

Emergent transcatheter arterial embolization in hemodynamically unstable patients with blunt splenic injury

RATIONALE AND OBJECTIVES

Splenic preservation is currently the trend for treatment of patients with splenic trauma to avoid complications of splenectomy. This study aimed to evaluate the feasibility of emergent transcatheter arterial embolization (TAE) for hemodynamically unstable patients with blunt splenic injury.

MATERIALS AND METHODS

In a period of 2 years, 65 patients of blunt splenic trauma were studied. Patients with initial systolic blood pressure < 90 mmHg and showed initial response including rapid response and transient response to the emergent fluid resuscitation were included. Angiography and TAE was undertaken if contrast medium extravasation or pseudoaneurysm formation was noted in the computed tomography (CT) images, according to the criteria of American Association for the Surgery of Trauma. All patients who underwent TAE were admitted for observation of the possibility of delayed rupture.

RESULTS

Thirteen hemodynamically unstable patients who were responsive to initial fluid resuscitation received angiography due to abnormal CT findings including contrast agent extravasation in 12 patients, 2 patients with arteriovenous fistula, and 8 patients with pseudoaneurysm formation. TAE was successfully performed in all of these 13 patients, including 2 patients with associated left renal injuries and 1 patient associated with bilateral internal mammary arteries injuries, without complications.

CONCLUSIONS

TAE is a safe and effective procedure for treating blunt splenic injury even in hemodynamically unstable patients who responded to initial fluid resuscitation.

Vascular disease of the spleen

A wide range of vascular disorders can affect the spleen. Although clinical presentation is often nonspecific, early diagnosis and treatment are mandatory in most conditions. Noninvasive imaging techniques are well suited to meet these objectives. Familiarity with normal macroscopic and microscopic vascular anatomy is a prerequisite to understand the pathophysiology of vascular disorders of the spleen. This article deals with diseases of the splenic vasculature (aneurysms, arteriovenous fistula, splenic vein thrombosis, collateral circulation in portal hypertension) as well as vascular disorders affecting the splenic parenchyma (splenic infarct, Gamna-Gandy bodies). Primary vascular tumors and tumor-like conditions of the spleen will be discussed very briefly.

Use of splenic artery embolization to relieve tense ascites following liver transplantation in a patient with paroxysmal nocturnal hemoglobinuria

Recurrent venous thrombosis following liver transplantation for Budd-Chiari syndrome is common, particularly in the setting of an underlying myeloproliferative disorder. We describe a patient who developed refractory ascites due to portal vein thrombosis following liver transplantation for Budd-Chiari syndrome in the setting of paroxysmal nocturnal hemoglobinuria. Extensive portal vein thrombosis, dense abdominal adhesions, and portosystemic collaterals precluded the use of a transjugular intrahepatic portosystemic shunt or surgical portosystemic shunt to manage the patient's ascites. Splenic artery embolization to decrease portal hypertension was performed, and this resulted in complete resolution of ascites. This case demonstrates the successful use of splenic artery embolization to manage ascites due to portal vein thrombosis following liver transplantation. Splenic artery embolization may be considered as an alternative option for the management of refractory ascites due to portal hypertension in patients who are unable to undergo safe transjugular intrahepatic portosystemic shunt or surgical shunt placement.

Coil Embolization of Splenic Artery Aneurysm with Preservation of the Parent Artery Using a Neck Remodeling Technique

We describe a case of a large and wide neck splenic artery aneurysm, treated by coil embolization using a balloon neck remodeling technique. The patency of the splenic artery was preserved without technical complications. This method should be considered as an alternative method for transcatheter management of splenic artery aneurysms.

Pearls and Pitfalls in Interpretation of Abdominal and Pelvic PET-CT

The interpretation of images obtained in the abdomen and pelvis can be challenging, and the coregistration of positron emission tomographic (PET) and computed tomographic (CT) scans may be especially valuable in the evaluation of these anatomic areas. PET-CT represents a major technologic advance, consisting of generally complementary modalities whose combined strength tends to overcome their respective weaknesses. However, this combined functional-structural imaging approach raises a number of controversial questions and presents some unique interpretative challenges. Accurate PET-CT scan interpretation requires awareness of the various pitfalls associated with the imaging components, both individually and in combination. The results of recent PET-CT studies have been very encouraging, but larger prospective studies will be needed to establish optimal hybrid scanning protocols. Applying sound imaging principles, paying attention to detail, and staying abreast of advances in this exciting new modality are necessary for harnessing the full diagnostic power of abdominopelvic PET-CT.