Iatrogenic Iliac Vein Injury Following Extracorporeal Membrane Oxygenation Cannulation in a Patient with May-Thurner Syndrome: A Case Report and Literature Review.

A 53-year-old woman presented with dyspnea. She had undergone extended thymectomy for an invasive thymoma two months prior. CT revealed numerous small nodules in the lung. After that, she deteriorated owing to acute respiratory distress syndrome (ARDS), and the vascular surgeon planned veno-venous extracorporeal membrane oxygenation (ECMO). During percutaneous cannulation through the left femoral vein, a vascular injury was suspected, and the patient's vital signs became unstable. Diagnostic angiography showed a ruptured left common iliac vein, and the bleeding was stopped by placement of a stent-graft. May-Thurner syndrome was diagnosed on abdominal CT. Here, we report a rare case of ECMO-related vascular injury in a patient with an unrecognized anatomical variant, May-Thurner syndrome. Copyrights

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a useful urgent treatment for patients with severe respiratory failure and veno-venous ECMO is the most common extracorporeal life support technique (1). ECMO has improved with equipment and technology, which led to a decrease in treatment-related complications. Because percutaneous vascular cannulation has to be performed for the initiation of ECMO, vascular injuries remain as an important cause of morbidity and mortality related to ECMO. We present a case of cannulation-related vascular injury in a patient with an undetected anatomical variant.

CASE REPORT

Informed consent has been obtained from patient's family for publication of the case report and accompanying images. A 53-year old female presented to our emergency room with chief complaints of dyspnea. She underwent extended thymectomy from invasive thymoma at the anterior mediastinum 2 months ago and the patient had been taking immunosuppressants such as cyclosporine and steroid because of the comorbidity like pure red cell aplasia. At the time of admission, numerous small nodules were noted on the chest CT, confirmed as cytomegalovirus pneumonia by bronchial washing. Despite noninvasive mechanical ventilator support, the acute respiratory distress syndrome (ARDS) deteriorated and clinicians performed the ECMO. The vascular surgeon planned veno-venous ECMO which meant both femoral veins were used for drainage and perfusion. During the percutaneous venous cannulation through the left femoral vein under ultrasound-guided, the vascular surgeon encountered resistance. Afterwards, the patient's vital signs became unstable and bleeding was suspected. Thus, after performing veno-arterial ECMO with right femoral artery and vein as the perfusion and drainage site because other venous access such as internal jugular vein was not possible due to the patient's severe obesity, vascular surgeon asked the interventional radiologist for diagnostic angiography. The patient's severe obesity prevented access to other veins such as internal jugular vein, so veno-arterial ECMO was performed through right femoral artery and vein as the perfusion and drainage site, and the vascular surgeon asked the interventional radiologist for diagnostic angiography.

The patient's left common iliac vein (CIV) was compressed between right common iliac artery (CIA) and lumbar vertebral body, which was confirmed by abdominal CT taken 8 days ago. Thus, we suspected May-Thurner syndrome. And there was an iliac vein variation that was a communicating vein from the right internal iliac vein (IIV) to the contralateral CIV (Fig. 1A, B) (2). An urgent angiography through the left common femoral venous access was performed using the 7-Fr vascular sheath, which revealed contrast extravasation arising from the left CIV (Fig. 1C). The vascular injury caused by an ECMO cannulation was strongly suspected. Thus, balloon tamponade for five minutes was initially attempted for the bleeding using a 10 mm × 60 mm Mustang balloon (Boston Scientific, Galway, Ireland). Because postangiography showed persistent bleeding, a larger balloon (12 mm × 60 mm) (Boston Scientific) was applied for 5 minutes. However, the bleeding was not stopped on the post-balloon angiography. After that, we decided on placement of the stent-graft. The diameter and length of the proximal and distal landing zone were determined base on the abdomen CT. In general, an oversizing of 10–15% and a proper landing zone of > 20 mm are required. Because proximal and distal diameter of left CIA were 12 mm and 10 mm, the largest, 12 mm × 60 mm, stent-graft (S&G Biotech, Seongnam, Korea) in our institution was selected. To avoid a backflow from the communicating vein, it was superselectively catheterized using 2.2-Fr microcatheter (Progreat, Terumo, Tokyo, Japan) and was embolized using detachable microcoils such as three Interlock coil (Boston Scientific, Cork, Ireland) (size: 12 mm × 30 cm, 14 mm × 30 cm, 18 mm × 50 cm) and one Concerto coil (Covidien, Plymouth, MN, USA) (size: 16 mm × 40 cm). Subsequently, the stent-graft were deployed over a 0.035-inch wire to cover the 15 mm distance between the proximal CIV and rupture site. After deployment, the stentgraft was dilated using a 12 mm × 40 mm Mustang balloon to achieve proper sealing. Postprocedure angiogram showed complete exclusion of the ruptured left CIV (Fig. 1D–F). Although the bleeding was successfully stopped with stabilized vital signs, the patient expired due to rapid aggravation of pulmonary infection three days after the procedure.

Fig. 1

Iatrogenic iliac vein injury with May-Thurner syndrome in a 53-year-old woman.

A. Axial CT shows compression of the left common iliac vein (black arrow) by the right common iliac artery (arrowhead). The white arrow indicates the right common iliac vein.

B. A 3D reconstructed CT scan shows communicating veins (black arrowheads) from the left common iliac vein (black arrow) to the right internal iliac vein (white arrowheads). The white asterisk and white arrow indicate the right common iliac artery and vein, respectively.

C. The left iliac venogram shows contrast extravasation from the rupture site (arrow) of the left common iliac vein. A communicating vein (black arrowheads) is noted between the left common iliac vein and the right internal iliac vein (white arrowhead).

D. A balloon tamponade is initially attempted to stop the bleeding using a 10 mm × 60 mm balloon catheter (arrow). Veno-arterial extracorporeal membrane oxygenation cannulas are inserted through the right femoral artery (white arrowhead) and vein (black arrowhead).

E. After the left internal iliac vein is embolized with detachable microcoils to avoid a backflow from the communicating vein, a 12 mm × 6 cm stent-graft (arrowheads) is deployed from the left common iliac vein to the external iliac vein.

F. After placement of the stent-graft, the venogram shows that there is no contrast extravasation and that patency of the left iliac venous system is restored.

DISCUSSION

Veno-venous ECMO is a rescue therapy in patients with severe respiratory failure. Most of the patients are cannulated via both femoral veins due to the easy access in an emergency condition (3). Insertion of large cannula through the femoral vessels can potentially lead to vascular complications including arterial limb ischemia, retroperitoneal hemorrhage, thromboembolism, dissection, pseudoaneurysm, and the groin infection (4). Thus, the cannulation should be performed under ultrasonography and/or fluoroscopic guidance. In case of anatomical problem, performing emergent ECMO on the bedside makes it difficult to avoid the vascular complications even with care. This case report described the significance of anatomical abnormality in cannulation process for ECMO. Upon reviewing CT, the patient showed compression of left CIV by overlying right iliac artery, widely recognized as May-Thurner syndrome (5). However, this was not realized at the time of ECMO cannulation because the iliac vein was not only well visualized by ultrasound but also the patient did not present significant symptoms such as deep venous thrombosis or venous hypertension Recent imaging study describes that compression of the left iliac vein at arterial crossover point may be present in 66% of the general population without venous symptoms (6). As the incidence of the left iliac vein compression is not rare and ECMO is increasingly used in various clinical scenarios, the probability of encountering vascular complication will inevitably increase.

Although the venous flow is low, iliac vein injuries can result in mortality up to 51% (7). In the past, emergent surgical repair has been the traditional method for the hemodynamically unstable patients because of disruption of the iliac veins (8). However, the endovascular covered stent placement for treatment of traumatic vascular injury has proven to be an effective alternative to open surgical repair (910). In this case, continued hemorrhage was noted even after balloon tamponade. Thus, we chose the covered stent which made immediate cessation of extravasation and restoration of venous patency.

Although it is difficult to predict anatomical variants by bedside observation, the complication could be avoided. This case raises the need to check the CT image for the anatomic variant such as iliac vein compression before urgent cannulation. Also, we recommended using fluoroscopy and ultrasound during cannulation and stopping the procedure if the guidewire is not advanced due to resistance or not visible in the inferior vena cava.