A Case of Bull Gore Injury Causing Pseudoaneurysm of the Lumbar Artery and Arteriovenous Fistula With Inferior Vena Cava

A re-bleeding retroperitoneal hematoma following surgical exploration for penetrating trauma is a challenging clinical scenario. Although initially sealed off by adventitial layers or surrounding tissues, the pseudoaneurysm underlying these hematomas may not be detectable, and may leak or rupture when the tamponade effect wears off after time passes or after sudden increase in intraluminal pressure.¹ The case report herein describes the role of a computed tomography (CT) angiogram and  angioembolization in managing such a situation.² Injury of the lumbar arteries is a cause of potentially life-threatening retroperitoneal hemorrhage,³ and traumatic lumbar artery injury causing arteriovenous fistula with inferior vena cava is extremely rare, with only one case reported in the literature.⁴ 

Case Report

An 18-year-old man presented at the emergency department with a pulse rate of 120 beats per minute and a blood pressure of 70/40 mm Hg. He had a history of bull gore injury to his left side lower abdomen that had occurred that morning (Figure 1). He had been initially taken to another center, where a laparotomy had been done. About 1.5 liters of hemoperitoneum were drained intra-operatively, and a mesenteric tear was repaired. There was no bowel injury. He had a zone 1, non-pulsatile retroperitoneal hematoma that had been left untouched. 

The patient had persistent hypotension in the immediate post-operative period and was referred to our center. On arrival, he was stabilized with intravenous fluids and one pint of blood. A wound was noted in the left iliac fossa, corresponding to the history of penetrating injury. His left side intra-abdominal drain had 200 mL frank blood on arrival and 20 mL additional blood per hour. A CT angiogram showed a pseudoaneurysm measuring approximately 20 mm × 10 mm arising from the right fifth lumbar artery, coming from the median sacral artery (Figure 2A). The pseudoaneurysm had a fistulous communication with the inferior vena cava (Figure 2B), and there was a diffuse hematoma in the surrounding retroperitoneum. The patient underwent angiography through a right femoral access, which confirmed the findings from on CT. The pseudoaneurysm was embolized using 4 mm × 6 mm MicroNester pushable coils (Cook Medical) that reduced the flow across the fistula. The residual stump of fistulous tract was embolized with 20% Histoacryl (B Braun Melsungen AG) (Figure 3). Post procedure, there was no output of blood from the drain. The patient had an uneventful recovery and was discharged in 8 days. 

Discussion

Lumbar arteries are in a series with the posterior intercostal arteries. There are four lumbar arteries on the right and left side of the body, which arise from the posterolateral aspect of the abdominal aorta, opposite the four lumbar vertebrae. A fifth, smaller pair may occasionally arise from the median sacral artery, but lumbar branches of iliolumbar arteries usually take their place.⁵ Lumbar artery injury and pseudoaneurysm may occur due to blunt or penetrating trauma, fall from height, or iatrogenic injury, or may occur spontaneously due to coagulation abnormalities.^2-4,6 Bull gore injury is an unusual cause of lumbar arterial injury. 

Contrast-enhanced computed tomography (CECT) or CT play a major role in detecting the site and extent of the vascular injury in trauma patients. CT may show a retroperitoneal hematoma, pseudoaneurysm, arteriovenous fistula, dilution of contrast medium in peritoneal fluid, or sedimentation within a hematoma. Contrast extravasation, dilution, sedimentation in peritoneal fluid, or increasing size of a hematoma on serial CT examinations are signs of an ongoing bleed. 

Once the diagnosis is confirmed, early intervention is necessary, because pseudoaneurysms of the lumbar artery have a significant tendency to expand, bleed, thrombose, or embolize, resulting in distal ischemia.⁶ Operative control of lumbar artery bleeding is often difficult since the site of origin may not be readily isolated. Exploration of a retroperitoneal hematoma may compound bleeding by releasing the tamponade effect of the peritoneum and by exacerbating associated venous bleeding.³ In institutions with appropriately trained interventional radiologists and a supporting trauma service, arteriography with embolization is the treatment of choice.²

Some of the  indications for angiographic embolization following penetrating vascular injury are: (a) relatively stable patients, (b) unsuccessful surgical exploration, and (c) bleeding in the later postoperative period secondary to late complications.¹ Common embolization agents are gelfoam, coils, glue, and particles.⁷

During the occlusion of an arteriovenous fistula, there is a risk of migration of embolic material to the venous side. We placed coils to reduce the shunting, and we followed coil placement with glue injection for complete obliteration of the fistula. Another concern in embolizing lumbar arteries is the risk of inadvertent spinal cord embolization. The main arterial supply of the dorso-lumbar spinal cord usually derives from a single anterior radiculomedullary artery called the artery of Adamkiewicz, which rarely arises below the level of L2.^2,8 The patient might acutely experience rhabdomyolysis from lumbar muscle infarction, and, as a result, renal failure can occur. A late complication of retroperitoneal infarction is secondary infection.² These complications can be avoided by more selective embolization of the feeder vessel, whenever possible. 

Conclusion

CECT or CTA play a definite role in identifying the site and extent of vascular injuries secondary to trauma, aiding in the management of this clinical condition. Selective embolization is a safe and effective method to control active extravasation, as well as to prevent future hemorrhage from an injured lumbar artery. It is a valuable treatment option for bleeding control when surgery has failed and another operation is not desirable.  

Acknowledgements: We thank Pippa Deodhar, PhD, in helping us in editing this manuscript.

Disclosure: The authors report no financial relationships or conflicts of interest regarding the content herein.

Manuscript submitted July 25, 2019; manuscript accepted September 6, 2019..

Address for correspondence: Shyamkumar N Keshava, DNB, Professor, Department of Interventional Radiology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India, 632004. aparna_shyam@yahoo.com

REFERENCES

1. Velmahos GC, Demetriades D, Chahwan S, et al. Angiographic embolization for arrest of bleeding after penetrating trauma to the abdomen. Am J Surg. 1999;178(5):367–373. 

2. Sofocleous CT, Hinrichs CR, Hubbi B, Doddakashi S, Bahramipour P, Schubert J. Embolization of isolated lumbar artery injuries in trauma patients. Cardiovasc Intervent Radiol. 2005;28(6):730-735. 

3. Sclafani SJ, Florence LO, Phillips TF, et al. Lumbar arterial injury: radiologic diagnosis and management. Radiology. 1987;165(3):709-714. 

4. Lloyd TV. Traumatic lumbar artery-inferior vena cava fistula. J Trauma. 1980;20(2):188-189. 

5. Standing S. Posterior abdominal wall and retroperitoneum. In: Gray’s Anatomy, 39th ed. 2008; Churchill Livingstone, London: England. 

6. Kessel BJ, Habib FA, Thompson B, Bajayo DE, Shatz D. Lumbar artery pseudoaneurysm. Eur J Trauma. 2004;30(3):187-190. 

7. Dondelinger RF, Trotteur G, Ghaye B, Szapiro D. Traumatic injuries: radiological hemostatic intervention at admission. Eur Radiol. 2002;12(5):979-993. 

8. Lo D, Valleé JN, Spelle L, et al. Unusual origin of the artery of Adamkiewicz from the fourth lumbar artery. Neuroradiology. 2002;44(2):153-157.