Splenic torsion with involvement of pancreas and descending colon in a 9-year-old boy

Splenic torsion is an uncommon condition becoming clinically apparent when the spleen twists or rotates around the organ’s vascular pedicle. In the case of a wandering spleen the organ is only attached to an elongated vascular pedicle while the peritoneal attachments are absent. However, splenic torsion could also occur in patients with abnormal laxity of the splenic peritoneal attachments. We report a case of a splenic torsion due to absence of splenic ligaments with pancreatic volvulus and partial involvement of descending colon in a 9-year-old boy.

imaging findings Further diagnostics were conducted by magnetic resonance imaging (MRI) to assess the enlarged organ and other intraabdominal organs and to rule out malignancies. MRI revealed an enlarged and wedge-shaped spleen ( Figure 1A and C). No enhancement could be detected after i.v. contrast administration. The vascular structures could be best depicted in the coronary orientation of the MRI with signs of anti clockwise twisting of the vascular pedicle ( Figure 1B). The lack of enhancement in the T 1 weighted study was interpreted as global splenic infarction. The splenic enlargement and a rather hyperintense T 2 weighted signal was considered as a sign of edema and venous congestion due to the twisted vascular pedicle preventing blood drainage and subsequently leading to an enlargement of the spleen. There were also signs of poorly defined fluid in the surrounding tissues in the former splenic lodge as well as in the lower abdomen and pelvis.
Another relevant finding revealed by the MRI was an involvement of the pancreas. MRI showed an involvement of the pancreatic tail with a focal dilatation of the pancreatic duct, suggesting an obstruction of the main pancreatic duct ( Figure 1C). Further, MRI revealed kinking of the pancreatic tail (Figure 2A-F). No further pathological signal alterations of the pancreas were detectable. Also, MRI indicated an involvement of the descending colon, though, no signs of bowel obstruction were detectable. tReatment Emergent laparotomy was performed immediately after MRI examination. Access to the spleen was gained by an upper transverse abdominal laparotomy. The spleen was 25 cm in length and was translocated from the original location towards the midline of the abdomen directly underneath the abdominal wall ( Figure 3A). All suspensor ligaments that usually hold the spleen in place in its compartment were absent. aBstRaCt Splenic torsion is an uncommon condition becoming clinically apparent when the spleen twists or rotates around the organ's vascular pedicle. In the case of a wandering spleen the organ is only attached to an elongated vascular pedicle while the peritoneal attachments are absent. However, splenic torsion could also occur in patients with abnormal laxity of the splenic peritoneal attachments. We report a case of a splenic torsion due to absence of splenic ligaments with pancreatic volvulus and partial involvement of descending colon in a 9-year-old boy. The splenic vascular pedicle was twisted several times with thrombosis as well as dilatation of the splenic artery and vein with a diameter of at least 1 cm ( Figure 3B and C). The organ showed substantial hemorrhagic infarction. Due to the translocation of the spleen, the pancreatic tail was kinked and twisted several times, as suggested by the MRI, though, no signs of pancreatic organ damage were detectable. Also, the suggested entrapment of the descending colon could be confirmed, however, there were no signs of damage of the descending colon. There was no acute abdominal bleeding with regular perfusion of the abdominal organs except for the spleen. The splenic torsion was resolved, however, no reperfusion was detectable. Due to the extensive infarction and congestion of the organ, the spleen could not have been preserved and splenectomy was performed.
The patient recovered fast after surgery with regular bowel movements from the second day after surgery and without any digestion problems. The boy was discharged on day 9 after surgery. He received a postoperative vaccination against Streptococcus pneumoniae, Haemophilus influenzae Type B and Neisseria meningitides on day 14 after splenectomy. The recovery period was uneventful and the follow-up examination after 2 months was inconspicuous.

disCUssion
Splenic torsion is a rather uncommon condition associated with the absence, underdevelopment or hyperlaxity of splenic suspensory ligaments, which causes an increased mobility of the spleen. [1][2][3] In addition to that, a long vascular pedicle predisposes to acute or chronic intermittent torsion with or without infarction depending on whether congestion of the organ occurs or not. This condition is also referred to as "wandering spleen" with two peaks of incidence in children aged less than 10 years, as in this reported case, and in females of childbearing age. 1,4,5 This condition also accounts for 0.2-0.3% of all splenectomies. 3,6,7 The involvement of other organs are rather rare. Only a few cases reported a pancreatic involvement. 1,2,8,9 To the best of our knowledge there has been only one report about a splenic torsion with involvement of pancreas and descending colon. 1 Patients with a wandering spleen can highly vary in their clinical presentation, ranging from being asymptomatic with an incidental palpable mass or present with an acute abdomen due to splenic infarction. 1,3,6 A splenic torsion can be a reason for recurrent abdominal pain, mostly localized in the left upper abdomen. The patients describe a colic pain lasting for a few moments to several hours with complete remission. Recurrent torsions with spontaneously detorsions of the spleen are in discussion for this rare clinical finding. 10,11  Contrast-enhanced T 1 weighted MR-imaging (coronary view) reveals an enlarged, ischemic and translocated spleen towards the midline of the abdomen (A). T 2 weighted and fat-saturated imaging (coronary view) shows the so-called "whirl-sign" (arrow) representing the torsion of the splenic pedicle (B). Involvement of neighboring anatomical structures such as pancreas (arrow head) and descending colon (star) is shown in (B) and (C). In the axial orientation (C) the arrow head points to a dilated main pancreatic duct.
Imaging plays a major role in establishing the diagnosis. US with color-Doppler control may reveal an abnormal location of the spleen and detect a mass, usually located in the midline of the abdomen. US can deliver valuable information in the preoperative workup of splenic torsion, i.e. for the assessment of viability of the spleen, involvement of other organs and the "whirl sign". Therefore, US should be considered as a primary diagnostic and preoperative imaging tool. 12 However, the US examination depends highly on the examiner's skills and it is often limited by meteorism. 9,12 In this presented case, US was inconclusive mainly due to heavy meteorism as described, and hence, further imaging with MRI was needed.
Tomographic examinations such as contrast-enhanced CT or MRI examinations may add valuable information in the course of diagnostic workup and can be included in case of an inconclusive or incomplete ultrasound examination. The most common findings include an empty splenic fossa and a translocated spleen. Additionally, in tomographic examinations the so-called "whirl sign" can be described, which is considered to be a sign of the torsion of the splenic pedicle. 12,13 Contrast-enhanced MRI is able to assess splenic viability. The above-mentioned pathology was found on MRI.
Surgical treatment options of wandering spleen depend on the organ's viability. If the spleen shows proper reperfusion after resolving the splenic torsion, either open or laparoscopic splenopexy may be offered, due to the spleen's physiologic importance, especially in children, and the risk of post-splenectomy sepsis. 14 If, however, the spleen is substantially infracted, a partial subtotal resection or splenectomy should be considered. 1,5 After splenectomy it is recommended to perform vaccination against capsulated pathogens like pnemococcus, H influenzae and meningococcus. 15 leaRning points 1. Splenic torsion with the involvement of neighboring anatomical structures is an uncommon condition. 2. However, it should be considered in differential diagnosis of an acute abdomen, especially in pediatric patients. 3. Therefore, accurate preoperative imaging is mandatory.
Contrast-enhanced MRI is a suitable method to deliver valuable preoperative information regarding the spleen's viability and the possible involvement of other neighboring organs. However, due to limited availability of MRI, US should be the first choice in the diagnostic path.

aCknowledgements
We acknowledge support by the German Research Foundation and the Open Access Publication Funds of the Göttingen University.

Consent
Written consent for publication of the case and imaging data was obtained from the patient and his legal guardian.