The spleen is an organ often forgotten about despite its numerous physiological roles and common injury following abdominal trauma. Management of a damaged spleen is therefore very important to understand and can take the form of medical, surgical, or radiological interventions. Which is the best to use and when should we use it?

Splenic embolization was first described by Maddison in 1973 [1]. It involves selectively disrupting the arterial blood supply at the end arterioles resulting in partial splenic infarction, decreased spleen size and increased circulating platelet count [2]. The current internationally accepted indication for SAE is the presence of extravasation of contrast medium detected on CT scan [3].

Current guidelines and research focus on SAE being offered to stable patients with low grade splenic injuries as an adjunct to non-operative management (NOM) [4] [5] [6].

However, given the many benefits that this procedure offers and its great potential, it is limiting to use it only as an adjunct to NOM. In order to fully identify its strengths and weaknesses, research needs to study SAE both in isolation as well as compared to other treatment modalities. The literature review included in the following case report aims to do this.

Splenomegaly is an abnormal increase in spleen size and is the most common clinical splenic abnormality. William Osler once said “nearly all diseases of the spleen are of a secondary nature” [13]. Thus, whilst splenomegaly is often the first manifestation of disease, even in 1908 Osler was aware that numerous different pathologies manifest as splenomegaly, making it a diagnostic challenge [14].

Radiologically we can classify splenomegaly as:

Moderate—the largest dimension is between 11 - 20 cm.

Severe—the largest dimension is greater than 20 cm [15].

The pathophysiology of splenic enlargement varies with aetiology. In the case of acute infection such as endocarditis, there is increased workload of clearing antigens and producing antibodies. The spleen responds by increasing its capacity of reticuloendothelial cells to compensate splenic hyperplasia.

The spleen can also enlarge due to a vascular change. As a result of long-term liver disease and cirrhosis, portal hypertension can occur. The splenic vein drains into the hepatic portal vein however in portal hypertension this becomes congested and thus the splenic vein engorges due to the backlog [16].

As mentioned earlier, the spleen may also re-assume a haematopoietic role in adults with chronic anaemia. This extramedullary haematopoiesis is often exhibited in myeloproliferative disorders and causes an increase in spleen size to accommodate the added function.

Finally, as with any organ in the body, the spleen is a potential site for infiltration. This may either be invasion of foreign cells such as metastases, or neoplastic changes within resident immune cells as seen in lymphoma [16] [17].

The most feared complication of splenomegaly is splenic rupture, usually caused by blunt abdominal trauma. In very thin individuals, the degree of trauma can be minor and may even be unnoticed.

The reason splenic rupture is so dangerous is because life-threatening intraperitoneal haemorrhage may follow. If there is associated hypersplenism also present, haemorrhage is even more dangerous due to thrombocytopaenia slowing clot formation [16].

The following section will discuss the case of Mr. H, a 54-year-old gentleman whose story forms the centrepiece of this report and allows a case-based view on splenic pathology and management.

Between April and June 2020, Mr. H noticed his urine had become more “sticky”. On presenting to his GP, a diagnosis of diabetes mellitus was confirmed by HbA1c. A full blood count performed at the same time showed a profound iron deficiency anaemia and on further questioning, it became apparent that the patient had also experienced weight loss and a few episodes of night sweats. As a result, the patient was referred to a haematology lymphoid clinic where a CT scan showed a moderately enlarged spleen and some enlarged abdominal lymph nodes. CT-guided biopsy confirmed these changes to be due to a low-grade B-cell non-Hodgkin lymphoma. Due to being low grade, the initial management plan was to watch and wait.

By the end of January 2021 however, an MDT discussion decided that because the patient’s symptoms were worsening it would be suitable to commence treatment with R-CVP (rituximab, cyclophosphamide, vincristine, and prednisolone).

In April, Mr. H suffered a fall out of bed landing on his front sustaining a left-sided chest and abdominal injury. His A&E clerking notes reported that he was pale and shivering with confusion, hypotension and a tender and distended LUQ abdomen. A CT abdomen showed a splenic laceration with active bleeding and a large volume haemoperitoneum. His notes showed that a prior abdominal ultrasound revealed splenomegaly of 17.6 cm. The patient was given a blood transfusion and referred to the surgical emergency unit where a joint decision was made for Mr. H to be managed with SAE under IR.

During the procedure, a focal active bleed was found at the lower splenic pole, supplied by multiple splenic branches. These were selectively cannulated with a co-axial microcatheter and embolised with multiple micro-coils. No further bleeds or abnormalities were seen and the splenic artery supply to the majority of the spleen was preserved. Mr. H suffered no post-procedure complications and on examination his abdomen was distended but soft with some tenderness on palpation but no signs of bleeding.

Patients who injure their spleen can broadly be categorised into those who are unstable, and those who are stable. Unstable patients generally undergo laparotomy and splenectomy due to the emergent nature of the injury and the increased risk of mortality [20]. Stable patients with lower grade injuries are treated more conservatively with non-operative management (NOM), with or without SAE added as an adjunct to increase the success rate of NOM [20] [21] [22].

SAE can be categorised into two main types – proximal and distal. Proximal SAE (PSAE) acts to decreases systolic arterial perfusion pressure whilst simultaneously promoting haemostasis and healing due to maintenance of blood flow via collateral pathways. Distal SAE (DSAE) is more beneficial in cases of focal injury. Given that blunt splenic trauma more commonly causes a multifocal injury, it is unsurprising that PSAE is the more commonly carried out procedure [23].

Figure 2 shows the major blood vessels supplying the spleen. The splenic artery is one of three branches of the coeliac trunk. Its first large branch is typically the dorsal pancreatic artery which bifurcates into left and right branches; the left branch continuing as the transverse pancreatic artery. The second large branch of the splenic artery is the greater pancreatic artery.

SAE is typically performed via a trans-femoral approach. The coeliac trunk is engaged using a 5 Fr reverse curve catheter. Coeliac angiogram is then performed, with images evaluating splenic artery patency, tortuosity, size, and pattern of injury. The other branches of the coeliac trunk are also evaluated as these will be important in supplying collateral perfusion to the spleen following PSAE.

To perform DSAE, a microcatheter and microwire are advanced to the site of the vessel injury and embolisation occurs with particles, glue (such as N-butyl cyanoacrylate), gel-foam and/or coils. For PSAE, vascular plugs and/or coils can be used between the dorsal pancreatic artery and great pancreatic artery. Alternatively, PSAE can be performed following DSAE, the rationale for this combined approach being that some vascular injuries may not be visible on initial angiogram and may lead to delayed bleed once vasospasm subsides [24] [25].

As mentioned earlier, other interventions for managing splenic pathology do exist, so why do we perform SAE?

How does IR SAE compare against its surgical counterparts? 30 years ago, the world of surgery was celebrating the innovation of laparoscopic techniques, has IR made those redundant?

Some of the benefits of SAE over surgery have already been mentioned such as the reduced invasiveness of IR as well as the functional splenic mass that is left over. Both allow for faster recovery and fewer long-term complications associated with asplenia [14] - [19]. For such reasons, many trauma centres are now performing more embolisation procedures than splenectomies [21] [25].

However, to say that SAE is better than a surgical approach is too simplistic.

Before the rise of IR, splenectomy was commonly performed in cases of splenomegaly increasingly laparoscopically. The advantages of such minimally invasive surgery were dramatic on their impact on postoperative pain, morbidity, and length of hospitalisation. The views that modern laparoscopes allow, give clarity in viewing anatomical structures allowing careful navigation around the many splenic vessels, such that they can be safely and appropriately ligated and transected [13].

Where laparoscopic splenectomy (LS) is a weaker intervention are in cases of massive splenomegaly where open splenectomy (OS) is a safer alternative. In fact, studies have shown that the most dangerous operations were those where initial LS had to be converted to OS due to the large size of the spleen [27]. Thus, spleen size is a very important factor when deciding which intervention will be the most beneficial [12] [28].

It is also important not to forget the importance of NOM and the large shift towards NOM in the past decade. The benefits include there being even less risk of infection with encapsulated bacteria compared to SAE. Furthermore, it can be helpful in cases where a patient may not be fit enough for invasive intervention.

The disadvantages of NOM include a risk of delayed splenic rupture, the possibility of re-bleeding as well as complications of embolisation. A more niche point is that unlike with surgical intervention, with NOM there is no intra-operative view that can be obtained of other visceral organs allowing less of an assessment of overall disease progress [15].

A study in 2016 showed that just under 200,000 people die each year from injury, 1 person every 3 minutes [29] [30]. The prevalence of intra-abdominal injury amongst emergency department patients is around 15%, and the spleen is the most injured organ in blunt abdominal trauma [30] [31].

This case report has used the example of Mr. H to discuss the different managements of splenic laceration. We have seen that SAE is becoming increasingly popular due to its reduced invasiveness, minimal splenic disruption, and faster recovery times with fewer post-op complications. That said, its surgical counterparts are still advantageous depending on both the degree of splenomegaly, and the stability of the patient.

The future of this field therefore needs to allow SAE to become its own stand-alone therapy rather than just being an adjunct to NOM. Furthermore, research needs to investigate which cohorts of patients are best suited to which intervention such that we can capitalise on the advantages of each intervention for the benefit of all. Figure 3 shows one example of how we may divide up these interventions, it could be altered to fit different criteria such as AAST grade of injury.

Hopefully, this report has made it clear that regarding management of the spleen, IR is a rising star but currently I do not believe that it can replace surgical intervention altogether.

The author declares no conflicts of interest regarding the publication of this paper.

Somanathan, A. (2022) The Role of Interventional Radiology in Splenic Trauma. International Journal of Clinical Medicine, 13, 548-559. https://doi.org/10.4236/ijcm.2022.1311041