Question & Answer

Radiology Imaging

Jeffrey W. Hanna, MD

From the Department of Radiology, Greenville Health System, Greenville, SC (J.W.H.)

Patient Description hip replacement, and jaw surgery. MRI of the left 65-year-old woman presents with 12 hip/ and lumbar spine were performed to months of low back pain radiating into further evaluate for structural causes of her pain Athe left leg. Previous history of surgeries (Fig 1.). Based on the below images, what is this includes breast reduction, abdominoplasty, right patient’s diagnosis? Answer on following page.

Imaging Figure 1 MRI of patient’s left hip/pelvis and lumbar spine.

Figure Legend: A) Coronal T1 image of upper pelvis; B) Coronal T1 image of the lumbar vertebra; C) Axial T2 image at level of L4/5 disc; D) Sagittal T2 of lateral lower lumbar spine.

GHS Proc. June 2017; 2 (1): 5-7 5 Answer Figure 2 Retro-psoas right common iliac .

Figure Legend: A) Coronal T1 image demonstrates abnormal C) Axial T2 image at level of L4/5 disc shows common iliac origin of right (arrows) with nearly 70° angle artery (CI) at lateral margin of the right intervertebral foramen from . B) Coronal T1 image further posteriorly shows right abutting the right L4 nerve root (arrow). D) Sagittal T2 shows CI common iliac artery (arrow) posterior to the psoas muscle along coursing caudally along the lateral margins of the L4/5 and L5/S1 the posterior third of the 4th and 5th lumbar vertebra contiguous right intervertebral foramina with the right L5 nerve root (arrow) with the lumbosacral plexus. seen just caudal to the artery.

Retro-Psoas Right Common these include singular reported cases by Vohra Iliac Artery in 1991,1 Sonneveld in 1998,2 Jain in 2008,3 Delasotta in 2012,4 and Yang in 2015.5 Overall, This anomaly of the iliofemoral arterial system it appears the anomaly was incidental to the is rare. Just a few cases have been published patient’s presenting symptoms and/or pathology describing this anomaly over the last 25 years; in all reported cases.

6 GHS Proc. June 2017; 2 (1): 5-7 QUESTION & ANSWER: RADIOLOGY IMAGING

The patient reported by Vohra had iliac artery ste- Significance Correspondence 1 nosis, but no causation was suggested. Sonneveld Delasotta initially raised the concern that the Address to: discovered the anomaly as an incidental finding position of the retro-psoas iliac artery could pose Jeffrey W. Hanna, MD, with unrelated but clinically significant abdominal an unexpected hemorrhagic problem in manag- Greenville Health 2 aortic aneurysm. Jain encountered this anomaly ing patients with lumbar disc disease.4 Whether System, Department 3 in the setting of iliac fossa renal transplantation, being managed by discectomy or transforaminal of Radiology, and Delasotta was evaluating a patient for possi- steroid injection, the juxtaposition of this vessel 1210 W Faris Rd, 4 Greenville, SC 29605 ble spinal fusion through a far lateral approach. may cause difficulty. Finally, Yang et al discovered their case in the ([email protected]) evaluation of a patient requiring pelvic surgery for While vascular complications from these pro- urothelial malignancy.5 Unlike the more common cedures are uncommon, life-threatening hem- iliofemoral anomaly of a persistent sciatic artery, orrhage from vascular injury in far lateral disc which is predisposed to aneurysm formation, the surgery7 and caudal spine cord infarction in few reported cases of retro-psoas iliac artery were foraminal steroid injections have been reported.8 found incidentally. Furthermore, the incidence of far lateral disc protrusions attributed as the source of radicular Embryology symptoms has increased, incidence of far lateral The lower limb vasculature arises as a continua- disc herniation ranging between 0.7%–1.7% of all tion of the but largely degen- disc herniations, with the increased use of MRI erates. The external iliac artery becomes its pri- for diagnosis.9 mary supply, which arises from the fifth lumbar intersegmental artery.6 Certainly, the limited surgical exposure and close approximation of the retro-psoas iliac artery to Sonneveld proposed that “the common iliac the far lateral disc protrusion will make knowl- and external iliac are derived from the edge of this anomaly before the surgical approach umbilical arteries at the end of the fourth week helpful. Similarly, the typical posterolateral of gestation. The umbilical arteries develop a sec- approach to transforaminal epidural steroid ondary connection to the fifth lumbar interseg- injection results in high likelihood of arterial mental branches of the aorta; these new trunks puncture. form the common iliac arteries from which the external iliac arteries subsequently arise. It may Overall, while the retro-psoas iliac artery is not be possible that the retro-psoas iliac artery in our associated with an apparent inherent increase in case embryologically was derived from an abnor- pathology, the few reported cases have illustrated mal secondary connection between the umbilical how knowledge of this anomaly may reduce the artery and the fourth, instead of the fifth, lumbar likelihood of difficulty when involved with pelvic intersegmental artery.”2 or lumbar surgical procedures.

References

1. Vohra R, Leiberman DP. An anomalous right iliac retro-psoas iliac artery: a case report. J Radiol Sci. artery presenting as iliac stenosis. Eur J Vasc Surg. 2015;40:13-6. 1991;5:209. 6. Schoenwolf GC, Bleyl SB, Brauer PR, Francis-West 2. Sonneveld DJ, van Dop, HR, van der Tol A. Anom- PH. Larsen’s Human Embryology. (5th edition) Else- alous retro-psoas iliac artery in a patient with an vier, Churchill Livingstone, Philadelphia (2015). abdominal aortic aneurysm. Eur J Vasc Endovasc 7. Harrington JF Jr. Far lateral disc excision at L5–S1 Surg. 1998;16:85-6. complicated by incursion: case 3. Jain A, Patil VP, Horton P, et al. Common iliac report. Neurosurgery. 2001;48:1377-9. artery lying posterior to psoas major identified 8. Murthy NS, Maus TP, Behrns CL. Intraforaminal during kidney transplantation. Transplantation. location of the great anterior radiculomedullary 2008;86:623-4. artery (artery of Adamkiewicz): a retrospective 4. Delasotta LA, Radcliff K, Sonagli MA, Miller L. review. Pain Med. 2010;11:1756-64. Aberrant iliac artery: far lateral lumbosacral surgical 9. Al-Khawaja DO, Mahasneh T, Li JC. Surgical treat- anatomy. Orthopedics. 2012;35:e294-7. ment of far lateral lumbar disc herniation: a safe and 5. Yang CJ, Tzeng WS, Shu G, Cheng HM. Anomalous simple approach. J Spine Surg. 2016;2:21-4.

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