Spring coil displacement after interventional embolization of severe pelvic fracture: a case report

Abstract

Haemorrhagic shock, which arises as a complication of pelvic fracture subsequent to severe trauma, represents a perilous state. The utilization of interventional endovascular haemostasis assumes a pivotal role in the management of patients with vascular injury following pelvic fracture. This article reports the treatment of a patient with pelvic fracture caused by a serious work-related vehicle accident. Despite the implementation of timely blood and fluid transfusion to combat shock, the application of aortic balloon obstruction, and interventional iliac artery embolization for haemostasis, the patient’s condition failed to display any discernible improvement. Repeat angiography further revealed a displacement of the interventional embolization material, and the patient subsequently died of multiple organ failure. The occurrence of spring coil displacement is infrequent, but the consequences thereof are considered grave, necessitating meticulous discernment in the selection of haemostatic materials for this type of patient. The diagnostic and therapeutic processes encompassing the particular case described here were analysed and are discussed with the objective of augmenting the efficacy and success rate of treatment modalities for patients in similar circumstances.

Introduction

Pelvic fracture, stemming from severe trauma caused by traffic accidents, heavy objects, and other forms of direct violence and extrusion, is often accompanied by concurrent injuries to neighbouring pelvic organs or vascular structures, thereby giving rise to the potential development of haemorrhagic shock. ¹ The majority of affected individuals belong to the young adult demographic and often experience an abrupt onset of symptoms, with rapid disease progression. ² Consequently, the perioperative period poses a heightened risk of lost surgical opportunities or a poor postoperative prognosis. Emergency interventional arterial embolization presents several advantages, including reduced preparation time, short operation time, and precise location of the bleeding site, thereby facilitating accurate haemostasis. ³ Functioning as a minimally invasive diagnostic and therapeutic tool, interventional arterial embolization exhibits the additional benefits of minimal trauma and precise haemostatic efficacy. Consequently, this procedure has gained widespread application in the management of patients with multiple injuries, particularly those with pelvic fractures and haemorrhagic shock. ⁴ The present case report describes the diagnostic and therapeutic course of a male patient in his early 60 s who underwent endovascular intervention with poor therapeutic results. Subsequent reimaging, conducted within a brief time frame, revealed the migration of embolic material and the patient died of multiple organ failure.

Case report

In March 2023, a male in his early 60 s experienced a work-related accident wherein he was crushed by an engineering vehicle, resulting in significant lower body trauma that exposed the underlying soft tissues and bones of the pelvis. Moreover, large areas of skin on both lower limbs were extensively torn, leading to profuse haemorrhaging. The patient was previously healthy and had no chronic cardiovascular diseases, such as hypertension. Immediately following the incident, the patient experienced delirium. Within 30 min of injury, the patient was transported via ambulance to Haining People’s Hospital. During transfer to the emergency room, the patient exhibited a body temperature of 35 °C, heart rate of 52 beats/min, respiration rate of 8 breaths/min, blood pressure of 71/35 mmHg, and an oxygen saturation level of 82%. Approximately 1 min after arrival to the emergency room, the patient experienced a cardiopulmonary arrest, prompting immediate resuscitative measures, such as cardiac chest compression, endotracheal intubation, and intracardiac epinephrine administration. Return of spontaneous circulation (ROSC) was achieved after approximately 10 min, with the patient exhibiting a blood pressure of 75/52 mmHg. To maintain blood pressure, a micropump infusion of norepinephrine at a rate of 0.95 μg/kg/min was administered. Additionally, the patient underwent pelvic band immobilization and received continuous transfusions of blood components, including 4 U suspended red blood cells, 10 U platelets, and 1000 ml of plasma, along with 1000 ml of lactated Ringer’s solution for volume resuscitation. Despite these interventions, the patient’s blood pressure remained unstable, dropping to a low of 59/33 mmHg. Following consultation, the Multiple Disciplinary Team (MDT) from the Regional Trauma Centre recommended the initiation of resuscitative endovascular balloon occlusion of the aorta (REBOA). The trauma surgery team at the local hospital promptly performed REBOA by accessing the almost exposed femoral artery on the right side of the patient, targeting zone III for occlusion. Subsequent to the procedure, the patient’s blood pressure increased to 70/40 mmHg. As the Haining People’s Hospital was unable to provide the necessary follow-up care, the patient was transferred to the Advanced Trauma Centre of the First Hospital of Jiaxing for further treatment while receiving ventilator support.

Upon arrival at the Emergency Department of the First Hospital of Jiaxing, the patient exhibited a state of unconsciousness, necessitating ventilation via a volume control mode with a tidal volume of 8 ml/kg, respiratory rate of 19 breaths/min, positive end-expiratory pressure of 8 mmHg, and an oxygen concentration of 100%. The patient presented with cold and clammy skin, rendering the measurement of SPO₂ and blood pressure unattainable. Palpation of carotid arteries revealed pulsation. The bilateral pupils were equal in size at approximately 0.4 cm in diameter, however, pupillary reflex to the light was diminished. Auscultation of the lungs detected thick respiratory sounds, devoid of murmurs. Wet rales were audible. Cardiac rhythm was regular and no murmur was discernible. The abdomen exhibited softness, lacking muscular tension, while the pelvic skin displayed avulsion. Notably, the exposed intestinal tube, as well as the presence of the REBOA catheter and deep venous cannula in the right groin, were observed. The radial artery pulse was feeble. Bilateral avulsion of the skin in the upper thigh region, accompanied by contusions of muscular and tissue structures, was evident. Furthermore, deformities were noted in the lower limbs (Figure 1).

Figure 1.

Image of a male patient in his early 60 s, showing pelvic skin avulsion with exposed bowel, bilateral upper thigh skin avulsion, and muscle and tissue contused laceration following significant lower body work-related crush trauma.

The results of blood gas analysis were as follows: haemoglobin level, 65 g/l (normal range, 130–175 g/l); platelet count, 34 × 10⁹/l (normal range, 125–350 × 10⁹/l); total protein, 28.5 g/l (normal range, 65–85 g/l); albumin 13.6 g/l (normal range, 35–55 g/l); pH 7.257 (normal range, 7.35–7.45); base excess, –15.1 mmol/l (normal range, –3 – +3 mmol/l); and lactate level, 4.5 mmol/l (normal range, 0.5–2.2 mmol/l). Coagulation parameters indicated a prothrombin time of 20.6 s (normal range, 14.0–21.0 s), an activated partial thromboplastin time of 126 s (normal range, 30.0–43.0 s), a fibrinogen concentration of 1.14 g/l (normal range, 1.5–4.0 g/l), and a D-dimer level of 43 220 ng/ml (normal range, 0–500.0 ng/ml). The treatment regimen encompassed various interventions, including the intravenous infusion of 4 g human fibrinogen, 1000 U prothrombinogen complex, and transfusion of blood components (including 8 U packed red blood cells, 20 U platelets, and 1400 ml plasma). Additionally, 2500 ml lactated Ringer’s solution and 500 ml sodium bicarbonate by injection were administered to address acidosis. Symptomatic supportive measures were also implemented. At 10 min following admission, the patient experienced another cardiac arrest, prompting immediate chest compressions. Simultaneously, the REBOA catheter was repositioned to zone I for occlusion and ROSC was successfully achieved 5 min later. Subsequently, an immediate computed tomography examination was conducted, revealing multiple comminuted fractures in the pelvis (lateral compression type III) and the left upper femur (Figure 2), accompanied by soft-tissue hematomas and subcutaneous emphysema. Furthermore, findings included pelvic soft-tissue swelling, subcutaneous emphysema in the soft tissue of the abdominal wall and abdominopelvic cavity, contusion or rupture of the pelvic intestines, pneumatosis in the intrahepatic bile ducts, pneumatosis in the left subclavian vein, left cephalic arm vein and soft tissue of the left neck, as well as multiple rib fractures on both sides. As the patient’s bowel was exposed, the general surgery team recommended abdominal exploration after his vital signs stabilized. Despite rib fractures, the thorax was stable and thoracic surgery was unnecessary.

Figure 2.

Computed tomography scan images from a male patient in his early 60 s following significant lower body work-related crush trauma, showing: (a) axial view revealing comminuted fracture of the pelvis; and (b) coronal view revealing the pelvic fracture type – lateral compression type III.

Following discussion within the MDT, it was determined that immediate emergency interventional embolization should be prioritized. Under X-ray, both the internal and external iliac arteries were revealed to be injured (Figure 3), and gelatin sponge particles and spring coils were employed for embolization (Figure 4), effectively achieving occlusion of both vessels. Subsequent postoperative angiography revealed successful occlusion of both the internal and external iliac arteries, with no evidence of contrast extravasation from the distal segments. The proximal portion of the common iliac artery remained visible. After embolizing the external iliac artery, the femoral artery was not supplied, and the right femoral sheath was saved for the next angiography. Following the operation, the patient was transferred to the intensive care unit (ICU) for further care. Upon admission to the ICU, the patient experienced a temporary rebound in blood pressure, and vital signs demonstrated a degree of stabilization compared with prior measurements. However, 4 h later, the patient’s circulatory status deteriorated once again, necessitating the administration of high-dose hypertensive medication (2 µg/kg/min norepinephrine) to maintain adequate blood pressure. The patient’s haemoglobin levels continued to decline, prompting the need for emergency angiography (Figure 5). During this subsequent imaging procedure, a portion of the spring coil within the right iliac artery was discovered to have displaced into the left iliac artery. A further embolization was performed intraoperatively to address the ongoing bleeding. Despite these efforts, on the second day after the intervention, the patient’s vital signs were not stable due to multiple organ failure, ultimately leading to his death.

Figure 3.

X-ray angiography images from a male patient in his early 60 s following significant lower body work-related crush trauma, showing: (a) the right internal and external iliac arteries; and (b) the left internal and external iliac arteries.

Figure 4.

Pelvic angiogram from a male patient in his early 60 s following significant lower body work-related crush trauma, showing placement of spring coils and gelatin sponges in the bilateral iliac arteries for the first interventional angiography.

Figure 5.

Second pelvic angiogram from a male patient in his early 60 s following significant lower body work-related crush trauma, showing partial migration of the spring coil from within the right iliac artery (where it had been initially placed) into the left iliac artery.

The reporting of this study conforms to CARE guidelines. ⁵ The patient’s legal proxy provided written informed consent for publication of this case report and the accompanying images, and the report was approved by the ethics committee of The First Hospital of Jiaxing (No. 2023-LY-248).

Discussion

Pelvic fracture from high-energy trauma is often accompanied by various associated injuries and can lead to haemorrhagic shock, with a high reported mortality rate. ⁶ Indeed, studies have indicated that the mortality rate for patients with pelvic fracture and shock upon arrival at the emergency room is approximately 30%. ⁷ The primary cause of mortality in these cases is massive bleeding, with potential blood loss reaching up to 5000 ml. Bleeding may originate from injured cancellous bone, damaged soft tissues, and vascular injuries involving both veins and arteries. ⁸ Vascular injury-related bleeding is particularly critical and can be life-threatening if not promptly controlled. ⁹ The management of haemodynamically unstable pelvic fracture complicated by haemorrhagic shock necessitates the MDT aligning with the principles of damage control orthopaedics.

At present, pelvic banding has gained widespread use in the initial treatment of pelvic fracture. Pelvic banding fixation has been observed to reduce pelvic volume by approximately 10%, functioning similarly to an external pelvic fixation device. ¹⁰ In cases of haemodynamically unstable pelvic fracture, where haemodynamic instability persists despite fluid resuscitation and external fixation, additional interventions may be required to achieve haemostasis. These interventions include pelvic tamponade, internal iliac artery ligation, and arterial interventional embolization. ¹¹ Arterial interventional embolization involves the use of imaging techniques to identify the main vessels responsible for bleeding, then selective embolization of the internal iliac artery and its branches can be performed to control distal arterial haemorrhage. In the present case, the patient was unable to undergo external fixation due to severe destruction of the pelvic structure. Additionally, the patient had severe open abdominal injuries, rendering extraperitoneal tamponade ineffective. The morbidity and mortality rate associated with extraperitoneal tamponade is reported to be as high as 11%, ¹² with the extraperitoneal tamponade technique typically reserved for specific scenarios, including angiography, external pelvic fixation stenting procedures, and cases where haemodynamic instability persists despite blood transfusion. Endovascular interventional methods have emerged as the primary approach for managing arterial injuries resulting from pelvic trauma, due to their ability to rapidly identify bleeding sources and effectively control haemorrhage.^13,14 In the present case, the surgical procedure involved the dissection of both the bilateral internal and external iliac arteries. Subsequently, gelatin sponge particles and spring coil materials were chosen for the embolization procedure, resulting in successful haemostasis during the initial stage of treatment. This approach effectively blocked the bleeding vessels and achieved the desired outcome of controlling haemorrhage.

Arterial embolization techniques can be categorized as super-selective embolization and non-super-selective embolization. Super-selective embolization is typically performed in internal iliac artery branches and involves the use of various embolization agents, such as polyvinyl alcohol (PVA) particles, gelatin sponge particles, blank microspheres, and tissue adhesive, while non-selective embolization of the internal iliac artery often utilizes gelatin sponge particles. These agents are suitable for embolizing small-vessel bleeding. In cases of bleeding from branch vessels larger than 2 mm, spring coils are preferred. Granular embolic agents may be used to embolize end vessels before applying spring coils, to enhance the haemostatic effect. In general, super-selective embolization of target vessels is recommended to minimize the risk of ectopic embolization complications, however, some experts have proposed that super-selective embolization may be associated with a high risk of rebleeding. The specific embolization methods and materials may be selected based on intraoperative imaging findings and individual cases. ¹⁵

Commonly used embolization materials, such as PVA particles, gelatin sponge particles, inert microspheres, and spring coils, are employed to mitigate distal vascular pressure by blocking arteries. They rely upon the intrinsic coagulation mechanism of patients to expeditiously form a thrombus. Conversely, tissue adhesive is employed based on the principle that it promptly solidifies upon encountering blood, thereby swiftly occluding blood vessels and fulfilling its haemostatic function. Notably, some scholars have proposed the utilization of tissue adhesive in conjunction with spring coils, ¹⁶ with the aim of augmenting the success rate of timely haemostasis, and diminishing the incidence of distant rebleeding and the risk of ectopic embolism, while others have described selective embolization of renal artery branches using tissue adhesive, which not only yields beneficial outcomes but may also save time and cost compared with spring coils. ¹⁷ Furthermore, due to its fluidity, tissue adhesive possesses an advantage in scenarios where super-selective embolization proves challenging. Yonemitsu et al. ¹⁸ reported that tissue adhesive embolization demonstrates superior efficacy compared with micro-spring coils and gelatin sponges in patients with acute haemorrhage and coagulation dysfunction, suggesting it as a preferred embolization material. The dilemma of whether tissue adhesive alone or in combination with spring coils would have been more suitable in the present case, for the patient with coagulation disorders, remains unresolved. Nonetheless, it is important to acknowledge that incomplete vessel occlusion by tissue adhesive may result in ectopic embolization, leading to embolic events occurring in other locations. Concerns regarding tissue adhesive-induced ectopic emboli have been documented,^19,20 encompassing splenic infarction, renal infarction, intestinal obstruction, cerebral embolism, and pulmonary embolism, thereby warranting vigilance among interventional practitioners utilizing tissue adhesive.

Post-interventional displacement of spring coil is a serious complication. In the present case, the patient experienced unstable blood pressure upon returning to the ICU after initial successful embolization, and subsequent imaging revealed that the spring coil had migrated to the contralateral side. Several possible causes for this displacement may be considered. (1) Nursing staff manipulation: it is important to review the actions of nursing staff during the retention of the arterial sheath tube. The possible tube flushing with a dilute heparin solution due to inadequate suction may contribute to spring coil displacement; (2) Traumatic coagulopathy: late dissolution of the already formed thrombus may lead to spring coil displacement; (3) Coil characteristics: inappropriate size or poor coiling technique of the spring coil itself may contribute to its displacement; ²¹ and (4) Local tissue factors: inflammation, tissue oedema, or necrosis can potentially lead to spring coil displacement, which is more commonly observed as a delayed displacement. ²²

With the advancement of minimally invasive technology, an increasing number of trauma patients are being preserved through interventional treatment. This case report demonstrates that although the occurrence of spring coil displacement is infrequent, the consequences thereof are considered grave, necessitating meticulous discernment in the selection of haemostatic materials to enhance the efficacy of treatment in this type of patient.