Rei Mitsuyama, MS2, MD Student, Brown University

Summary:

            Spontaneous iliopsoas and rectus sheath hematomas arising in patients on anticoagulant therapy are more likely to require embolic treatment rather than conservative management. Of the numerous embolic agents available, Glubran 2 NBCA-MS glue seems to be an efficacious option that causes less inflammation and histotoxicity than standard glues, with greater ease of administration.

Intro and Background

            Spontaneous intramuscular hematoma is a rare clinical entity for which initial management is often conservative. However, it is a common and serious complication of anticoagulation therapy and its incidence has risen with the increased use of anticoagulation, especially in elderly patients [1]. The iliopsoas and rectus sheath are the main locations for soft-tissue hemorrhage.

Transcatheter arterial embolization (TAE) has become an important option for treating acute arterial bleeding [2]. Microcoils offer one option but placing them distally in small and tortuous arteries poses a challenge and can be time-consuming. n-butyl cyanoacrylate (NBCA) glue is another option but is less predictable than other embolic agents. Glubran 2 (GEM, Viareggio, Italy) is a surgical glue in which NBCA is combined with methacryloxy sulfolane (MS) to form a more pliable and stable polymer that elicits less inflammation and histotoxicity.

This retrospective review aimed to evaluate the safety and efficacy of n-butyl cyanoacrylate methacryloxy sulfolane (NBCA-MS) in treating spontaneous iliopsoas hematomas (IPHs) and rectus sheath hematomas (RSHs) in anticoagulated patients and to determine predictive factors of clinical success and 30-day mortality [3].

Study Population and Treatment Protocol

            From August 2011 to November 2016, fifty anticoagulated patients with spontaneous IPHs and/or RSHs and active bleeding on computed tomography (CT) received TAE with NBCA-MS. 25 were men and 25 were women with a median age of 71.2 ± 14.2 years (range, 19-87 years). The study excluded patients with recent trauma, other embolic agent treatment and hematoma secondary to a recent surgical site.

Contrast CT was used to localize hematomas and evaluate for active extravasation in the arterial phase followed by angiography to locate the extravasation. All angiographic procedures were performed by 1 of 3 interventional radiologists via percutaneous transfemoral catheterization. All actively-bleeding arteries were embolized with Glubran 2 NBCA-MS. If no active hemorrhage was found on angiography, the feeding artery was empirically embolized based on CT findings. For ISH, the bleeding ipsilateral lumbar artery was embolized; for RSH, the ipsilateral inferior epigastric artery was targeted.

Data Collection

            38 patients (76%) had IPH, 11 (22%) had RSH, and 1 (2%) had both. Hematoma size was measured as the approximate volume in cubic centimeters as defined by the maximum anteroposterior and transverse dimensions in the axial plane and maximum craniocaudal dimension in the sagittal plane.

            Several parameters were measured before embolization: mean blood pressure, units of RBCs given before embolization, platelet count, international normalized ratio (INR), hemoglobin level.

            Technical success was defined as complete occlusion of the target artery or cessation of extravasation on post-procedural arteriography. Clinical success was defined as absence of bleeding within 30 days following technically successful embolization.

Outcomes

            Technical success rate was 100% while clinical success rate was 66%. Clinical failure (n = 17; 34%) was related to persistent bleeding (n = 10) or recurrent bleeding (n = 7). All 10 patients with persistent bleeding died within 48 hours due to multiorgan failure resulting from hemorrhagic shock (defined as mean arterial pressure < 65 mmHg). Of the 7 patients who experienced recurrent bleeding, 1 was successfully treated conservatively, 1 was re-embolized successfully, 2 died following unsuccessful surgical attempts to control bleeding, and 3 died from hemorrhagic shock before further intervention.

            The 30-day mortality rate was 44% (n = 22). Deaths not attributed to bleeding were sepsis secondary to pulmonary infection (n = 4) and heart attack (n = 3). Fifteen were directly related to persistent bleeding (n = 10) or recurrent bleeding (n = 5).

            Major complications were rare and included a hematoma at the puncture site requiring surgical treatment, and 2 retroperitoneal abscesses treated successfully by percutaneous drainage.

            Lower MBP, greater number of RBC units infused before embolization, and greater volume of hematoma were significantly associated with lower clinical success rates. Clinical success rates were worse in IPH (61.5%) than RSH (100%). Clinical failure, lower MBP, and greater number of RBC units infused before embolization, were significantly associated with higher 30-day mortality.

            Of note, age, hemoglobin level, platelet count, and INR were not associated with clinical success or 30-day mortality.

Conclusions

            Transcatheter arterial embolization is an important treatment option for emergent treatment of anticoagulation-related arterial bleeds. With the multitude of embolic agents available, there are advantages to each. Glubran 2 NBCA-MS has a slow polymerization rate allowing more comfortable handling and release. Furthermore, it is cost-effective, with 1 mL comparable in cost and treatment success to a single pushing coil.

            Limitations of this study include those common to retrospective studies such as lack of a control group or comparison treatment groups. From this set of patients it is impossible to determine whether conservative measures would have been adequate in some cases or if other embolic agents may have produced different outcomes. While comparative retrospective series in literature utilizing other embolization modalities including coils, gelfoam, or NBCA resulted in better outcomes, it should be noted the cohorts in the current series were both older and exhibited a relative high proportion of poor prospective factors including active bleeding on CT and receiving anticoagulation. Another limitation, is that with no follow-up data, long-term outcomes are unknown at this time. Finally, some of the studied patients were given anticoagulation as a preventative measure and therefore had normal coagulation parameters, possibly leading to better outcomes in these patients relative to the others.

            Overall, this study showed that NBCA-MS is a safe and efficacious embolic agent in the treatment of anticoagulation-related IPH and RSH with an acceptable success rates despite the inherently high mortality and morbidity of these conditions. There are still many questions to be answered, such as which embolic agents are best used under which circumstances and if there is a critical time-frame during which embolization should be performed, as well as longer-term pros and cons of each. At the very least, NBCA-MS provides another reliable option in managing a potentially life-threatening condition and could be used in a setting requiring TAE.

References:

  1. Popov M, Sotiriadis C, Gay F, et al. Spontaneous Intramuscular Hematomas of the Abdomen and Pelvis: A New Multilevel Algorithm to Direct Transarterial Embolization and Patient Management. Cardiovasc Intervent Radiol 2017; 40:537–545. https://doi.org/10.1007/s00270-017-1590-8
  2. Nagarsheth KH, DuBose JJ. Endovascular Management of Vascular Trauma. Trauma 2015; 17(2) 93–101. https://10.1177/1460408614539624
  3. Jawhari R, Chevallier O, Falvo N, et al. Outcomes of Transcatheter Arterial Embolization with a Modified N-Butyl Cyanoacrylate Glue for Spontaneous Iliopsoas and Rectus Sheath Hematomas in Anticoagulated Patients. Vasc Interv Radiol 2017; article in press. https://doi.org/10.1016/j.jvir.2017.08.006