Journal of Neuroendovascular Therapy
Advance Published Date: May 11, 2015
Image of the Issue
A case of persistent sciatic artery encountered during cerebral aneurysm embolization Kittipong SRIVATANAKUL Takahiro OSADA Mitsunori MATSUMAE Department of Neurosurgery, Tokai University School of Medicine ● Abstract ●
The femoral artery is usually the main route of access in many endovascular procedures and diagnostic angiograms. A rare anomaly of persistent sciatic artery (PSA) was encountered during embolization of unruptured cerebral aneurysm. This report is to describe the clinical features and the embryological considerations of the PSA that interventionists should be aware of. ● Key words ●
persistent sciatic artery, anatomy, anomaly ＜ Correspondence Address: Kittipong SRIVATANAKUL, Department of Neurosurgery, Tokai University School of Medicine; 143 Shimokasuya, Isehara-shi, Kanagawa, 259-1193, Japan; E-mail:
[email protected] ＞ （Received February 5, 2015: Accepted April 2, 2015） doi: 10.5797/jnet.ioi.2015-0006
Case report
done to achieve hemostasis in the groin. Further investigation of this anomalous artery was
A 46-year-old woman with an unruptured aneurysm of
performed by contrast enhanced CT scans. The anomalic
the paraclinoid portion of the right internal carotid artery
vessel was found bilaterally and the final diagnosis of this
underwent coil embolization in our institute. A diagnostic
artery was the persistent sciatic artery (PSA) by its course.
angiogram was performed 2 months prior to the procedure.
Discussion
Several punctures of the right femoral artery were required at the time of diagnosis. The pulsation of the femoral artery was noticed to be very weak on both sides.
The PSA is a very rare anomaly observed only in 0.03% to 0.06% and bilateral presentation is reported to be 30%.1）
A 6 French introducer was inserted into the right femoral
The usual presentation is aneurysmal formation, ischemic
artery for the embolization procedure. Coiling of the
symptoms, or pain.1–5） It can be recognized as an artery
aneurysm was performed. Heparin was administered
arising from an enlarged internal iliac artery passing
during the procedure as a prophylactic protocol. At the end
through the greater sciatic foramen below the piriformis
of the procedure, prior to the use of hemostatic device, we
muscle to enter the thigh area. The vessel later on passes
did an angiogram of the right femoral artery to check the
into the popliteal fossa to join the popliteal artery.
caliber and the site of entrance of the introducer into the
Embryologically, the vessel is the remnant of the
artery. The femoral artery was found to be of small caliber.
umbilical artery branch supplying the lower limb bud
Another vessel, more prominent in its diameter, arose from
at the 6-mm embryo stage. At this stage, it runs to the
the internal iliac artery and coursed lateral to the femoral
extremity of the limb bud. The external iliac artery, on the
artery towards the distal part of the limb, was observed (Fig.
other hand, arising from the lateral aspect of the umbilical
1). The caliber of the femoral artery was considered too
artery develops further into the common and superficial
small to use a hemostatic device. Manual compression was
femoral arteries by the 12-mm stage. By the 18-mm stage
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Journal of Neuroendovascular Therapy
Advance Published Date: May 11, 2015
Srivatanakul K, et al
Fig. 1 Injection of the common iliac artery performed after the aneurysm embolization prior to the usage of the hemostatic device. The femoral artery is small in caliber (arrowheads). An anomalous vessel arising from the internal iliac artery, running lateral of the femoral artery can be identified. Notice the branching of the superior gluteal artery from this vessel (arrow).
the superficial femoral artery takes over the supply to the
cases of PSA, the internal iliac artery is enlarged and
popliteal artery and the sciatic artery regresses to become
this anomalous vessel runs lateral to the femoral artery
the inferior gluteal artery resulting in the femoral artery
in anteroposterior view. On axial images the vessel runs
4）
alone supplying blood to the branches beyond the knee.
posterior to the femoral artery system. The femoral artery
Depending on the degree of the anastomosis to the femoral
is usually hypoplastic in the settings of PSA (Figs. 2, 3).
artery system, the PSA can be in complete or incomplete form.
The PSA is an important anomaly to keep in mind during the access of the femoral artery apart from other conditions
Although the PSA is a rare anomaly, an interventionist
that might cause weakness in the pulse of the femoral
should be aware of its existence. The usual clinical
artery such as atherosclerotic conditions, fibromuscular
finding is weak pulsation of the femoral artery compared
dysplasia, coarctation of aorta, and aortitis syndrome.
to that of the popliteal artery. Difficulties in the puncture
We believe that the approach need not necessarily be
of the femoral artery with combination of the above
modified as long as the caliber of the femoral artery is
finding should raise suspicion of the PSA. Diagnostic
considered large enough for the endovascular approach.
imaging is quite classic. The course of the PSA can be
In case of unilateral PSA, contralateral femoral artery
easily recognized on conventional angiography and also
approach maybe the first alternative before considering
by other less invasive methods such as CT and MRI. In
other approaches such as the brachial approach. There is
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Journal of Neuroendovascular Therapy
Advance Published Date: May 11, 2015 Srivatanakul K, et al
Fig. 2 Maximum intensity projection image of CT done after the procedure. The persistent sciatic artery can be identified bilaterally (arrows). Both femoral arteries are hypoplastic (arrowheads). Note the posterior path of the persistent sciatic artery to the bone.
Fig. 3 Three-dimensional reconstruction of contrast-enhanced CT showing the course of the persistent sciatic artery (arrowheads). It travels through the greater sciatic foramen thus having the same path as the inferior gluteal artery.
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Journal of Neuroendovascular Therapy
Advance Published Date: May 11, 2015
Srivatanakul K, et al
no long-term follow-up report for asymptomatic PSA. We recommend that the patient be advised to avoid chronic trauma to the gluteal region such as sitting on hard surface. Periodic evaluation with non-invasive imaging is also an option. Educating the patient about PSA and its possible symptoms would help if problems occur in future. The authors declare that they have no conflict of interest. References 1）van Hooft IM, Zeebregts CJ, van Sterkenburg SM, et al. The
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persistent sciatic artery. Eur J Vasc Endovasc Surg 2009; 37: 585–591. 2）Aziz ME, Yusof NR, Abdullah MS, et al. Bilateral persistent sciatic arteries with unilateral complicating aneurysm. Singapore Med J 2005; 46: 426–428. 3）Ikezawa T, Naiki K, Moriura S, et al. Aneurysm of bilateral persistent sciatic arteries with ischemic complications: case report and review of the world literature. J Vasc Surg 1994; 20: 96–103. 4）Mandell VS, Jaques PF, Delany DJ, et al. Persistent sciatic artery: clinical, embryologic, and angiographic features. AJR Am J Roentgenol 1985; 144: 245–249. 5）Sindel T, Yilmaz S, Onur R, et al. Persistent sciatic artery: radiologic features and patient management. Saudi Med J 2006; 27: 721–724.
