Radiology Teaching Files > Case 7521497

Contributed by: patricia burrows, Radiologist, Children's Hospital Boston, Massachusetts, USA.
Patient: 2 year 7 month 28 day old male

The patient was born with a vascular mass evident in the perineum.  Fairly soon after birth he began to experience bleeding from the anal canal. He now bleeds both with and in between bowel movements. There is no bleeding from the skin surface. In addition, he has apparent pain while straining to have bowel movements. This results in inconsolable crying. His hemoglobin typically drops to about 7 grams before he is transfused. His father describes him having some fever and rigors prior to transfusion. A MRI scan shows prominent venous channels and subcutaneous soft tissues extending from the base of the scrotum to the anterior perineum. There is evidence of high flow indicated by some dilated internal iliac branches more proximally. There is minimal disruption of the soft tissues around the abnormal vessels. On clinical examination, there is a bulging area of bluish discoloration just behind the base of the scrotum on the left side apparently extending into the anal canal. This is compressible but warm and although not grossly pulsatile is more reminiscent of a high flow lesion than a pure venous malformation.


Fig. 1: MRI dated 01/01/2000 Patient 6 m.o.

Fig. 2: MRI dated 01/01/2000 Patient 6 m.o.

Fig. 3: MRI dated 01/01/2000 Patient 6 m.o.

Fig. 4: MRI dated 01/01/2000 Patient 6 m.o.

Fig. 5: Angio/Embo dated 01/08/2002 Patient 2 y.o.

Fig. 6: Angio/Embo dated 01/08/2002 Patient 2 y.o.

Fig. 7: Angio/Embo dated 07/11/2002 Patient 3 y.o.

Fig. 8: Angio/Embo dated 01/22/2003 Patient 3 y.o.

Fig. 9: Angio/Embo dated 01/22/2003 Patient 3 y.o.

Fig. 10: Angio/Embo dated 01/22/2003 Patient 3 y.o.

Fig. 11: Angio/Embo dated 01/22/2003 Post Embo Patient 3 y.o.

Multimedia: 7521751.avi
Fig. 12: Follow-up Angio dated 07/22/2004 Patient 5 y.o.


IMAGING FINDINGS: The arterio-venous malformation is confirmed by the angiography study. The arterial supply of the malformation is by a hypertrophied left internal pudendal artery. Distally, there is more than one major feeding branch. There is be recruitment of right-sided contralateral branches of internal pudental distally, but these are not marked. Further tiny arterial supply vessels are seen from the distal obturator and possibly anastomosing with inferior hemorroidal. No direct hemorrhoidal supply is seen on injection of inferior mesenteric artery. The malformation shows direct arteriovenous shunting with early venous filling. The draining veins are on the left side and appears as complex tortuous mass of varicosities extending laterally and medially in the perianal region. The tortuous draining veins appear to drain via small gluteal branches rather than a single large hypertrophied vessel.  After arterial embolization and venous sclerotherapy, check angiography performed at the aortic bifurcation shows that much of the arteriovenous malformation no longer fills. On late images, there are a few small foci of venous pooling, but much of the venous outflow and the arterial filling is no longer present. However, on the first check angiogram post embolization, contrast extravasation from the anal region was noted. This is seen as a contrast blush running down the skin of the inner right thigh. It was at this point that further embolization was performed with Sotracol opacified with Ethiodol 4:1. A final arteriogram shows no significant residual AVM filling or venous pooling. No extravasation was seen at this point. Clinically, the anal ulcer appeared dry.

CONCLUSION: Arterial embolization and venous sclerotherapy of an arteriovenous malformation of the left pudendal region.



ANGIOGRAPHIC FINDINGS: The initial angiogram shows residual arteriovenous malformation supplied by several tiny peripheral branches of the left internal pudendal artery and later shown the right internal pudendal artery. The shunts are tiny and they communicate with grape-like cluster of venous channels, subsequently draining into the left pudendal veins. The final angiogram shows obliteration of the AVM although there are some tiny dilated branches of the right internal pudendal arteries still evident. There is no venous shunting. The penile artery with the corporal blush is preserved.

OPINION: Residual or recurrent left perineal AVM. Technically successful arterial ethanol embolization with angiographic good result.


ANGIOGRAM: Angiogram of the pelvic vessels modrate demonstrated AV shunting in the right perianal region and in the expected location of the anal sphincter supplied primarily by the internal pudendal arteries with greater contribution from the right vessel. Post-procedural angiogram demonstrated significantly improved result. with only a tiny residual blush in the infrascrotal area. The IMA angiogram showed no AVM primarily in the rectum or anal canal.


Successful embolization and sclerotherapy of perineal AVM.



IMAGING FINDINGS: Angiography demonstrates normal arterial and venous anatomy in the pelvis. There is no arteriovenous shunting. The inferior mesenteric angiogram demonstrates normal rectal vascular anatomy with no abnormal vessels. On very late images of the right internal iliac angiogram, there is demonstration of some fine cutaneous channels in the medial right buttock. However these are not associated with any arteriovenous shunting or demonstration of any venous varices, as were seen previously.

CONCLUSION: No evidence of residual perirectal arteriovenous malformation.

Diagnosis: AVM of the perineum and anus treated with embolization and direct injection (X4) with excellent results (no residual AVM seen on follow-up - 07/04).
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Additional Details:

Case Number: 7521497Last Updated: 03-15-2007
Anatomy: Gastrointestinal (GI)   Pathology: Vascular
Modality: MR, AngiographyAccess Level: Readable by all users
Keywords: embolization

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