Shrapnel injuries are commonly encountered in war zones.1 Shrapnel injuries can remain asymptomatic or become systemic, with health effects of the retained foreign body ranging from local to systemic toxicities depending on the patient’s reaction to the chemical composition and corrosiveness of the fragments in vivo.2 We present a case of a reactivating shrapnel injury in the form of a retroperitoneal infection and subsequent iliopsoas abscess. A collaborative procedure was performed between surgery and interventional radiology to snare and remove the infected fragment and drain the abscess.
Case Presentation
While serving in Vietnam, a soldier sustained a fragment injury to his left lower abdomen. He underwent a laparotomy, small bowel resection, and a temporary ileostomy at the time of the injury. Nearly 50 years later, the patient presented with chronic left lower quadrant pain and a low-grade fever. He was diagnosed clinically in the emergency department (ED) with diverticulitis and treated with antibiotics. The patient initially responded to treatment but returned 6 months later with similar symptoms, low-grade fever, and mild leukocytosis. A computed tomography (CT) scan during that encounter without IV contrast revealed a few scattered colonic diverticula without definite diverticulitis as well as a metallic fragment embedded in the left iliopsoas with increased soft tissue density.
The patient was diagnosed with a pelvic/abdominal wall hematoma and was discharged with pain medication. The patient reported recurrent attacks of left lower quadrant pain, fever, and changes in bowel habits, prompting gastrointestinal consultation and a colonoscopy that was unremarkable. Ten months later, the patient again presented to the ED, with recurrent symptoms, a fever of 102 °F, and leukocytosis with a white blood cell count of 11.7 × 109/L. CT scan with IV contrast revealed a large left iliopsoas abscess associated with an approximately 1-cm metallic fragment (Figure 1). A drainage catheter was placed under CT guidance and approximately 270 mL of purulent fluid was drained. Culture of the fluid was positive for Escherichia coli (E coli). Two days after drain placement, the fragment was removed as a joint procedure with interventional radiology and surgery. Using the drainage catheter tract as a point of entry, multiple attempts were made to retrieve the fragment with Olympus EndoJaw endoscopic forceps without success.
Ultimately a stiff directional sheath from a Cook Medical transjugular liver biopsy kit was used with a Merit Medical EnSnare to relocate the fragment to the left inguinal region for surgical excision (Figures 2, 3, and 4). The fragment was removed and swabbed for culture and sensitivity and a BLAKE drain was placed in the evacuated abscess cavity. The patient tolerated the procedure well and was discharged the following day. Three days later, culture and sensitivity grew E coli and Acinetobacter, thus confirming infection and a nidus for the surrounding abscess formation. On follow-up with general surgery 7 days later, the patient reported he was doing well, and the drain was removed without difficulty.
Discussion
Foreign body injuries can be benign or debilitating depending on the initial damage, anatomical location of the foreign body, composition of the foreign body, and the patient’s response to it. Retained shrapnel deep within the muscle tissue rarely causes complications. Although many times embedded objects can be asymptomatic and require no further management, migration of the foreign body or the formation of a fistula is possible, causing symptoms and requiring surgical intervention.1 One case involved the formation of a purulent fistula appearing a year after an explosive wound to the lumbosacral spine, which was treated with antimicrobials. Recurrence of the fistula several times after treatment led to surgical removal of the shrapnel along with antibiotic treatment of the osteomyelitis.3 Although uncommon, lead exposure that occurs due to retained foreign body fragments from gunshot or military-related injuries can cause systemic lead toxicity. Symptoms may range from abdominal pain, nausea, and constipation to jaundice and hepatitis.4 The severity has also been stated to correlate with the surface area of the lead exposed for dissolution.5 Migration of foreign bodies and shrapnel to other sites in the body, such as movement from soft tissues into distantly located body cavities, have been reported as well. Such a case involved the spontaneous onset of knee synovitis due to an intra-articular metallic object that was introduced via a blast injury to the upper third of the ipsilateral thigh.1
In this patient’s case, a large intramuscular abscess had formed nearly 50 years after the initial combat injury, requiring drainage of the abscess and removal of the fragment. By snaring the foreign body to a more superficial site, the surgical removal only required a minor incision, decreasing recovery time and the likelihood of postoperative complications that would have been associated with a large retroperitoneal dissection. While loop snare is often the first-line technique for the removal of intravascular foreign bodies, its use in soft tissue retained materials is scarcely reported.6 The more typical uses involve the removal of intraluminal materials, such as partially fractured venous catheters, guide wires, stents, and vena cava filters. The same report mentioned that in all 16 cases of percutaneous foreign body retrieval, no surgical intervention was required.7 In the case of most nonvascular foreign bodies, however, surgical retrieval is usually performed.8
Surgical removal of foreign bodies can be difficult in cases where a foreign body is anatomically located next to vital structures.9 An additional challenge with a sole surgical approach to foreign body retrieval is when it is small in size and lies deep within the soft tissue, as was the case for our patient. In such cases, the surgical procedure can be time consuming and lead to more trauma to the surrounding tissues.10 These factors alone necessitate consideration of postoperative morbidity and mortality.