Sclerotherapy using absolute alcohol was subsequently performed under imaging guidance with complete resolution of the subcutaneous component of the ...
The British Journal of Radiology, 73 (2000), 80±82
E
2000 The British Institute of Radiology
Case report
Intraosseous venous drainage anomaly of the tibia treated with imaging-guided sclerotherapy 1
W C G PEH, FRCR, 2J W K WONG, FRCS, 1W K TSO, FRCR and 2E P CHIEN, FRCS
Departments of 1Diagnostic Radiology and 2Orthopaedic Surgery, The University of Hong Kong, Queen Mary Hospital, Hong Kong
Abstract. A 23-year-old man presented with a pre-tibial soft tissue mass. Magnetic resonance images demonstrated the subcutaneous, intracortical and intramedullary components of an intraosseous venous drainage anomaly, which was con®rmed by direct venography. Sclerotherapy using absolute alcohol was subsequently performed under imaging guidance with complete resolution of the subcutaneous component of the lesion.
Intraosseous venous drainage anomaly of the tibia has recently been described in association with pre-tibial varices in six patients [1]. We describe a patient presenting with intraosseous venous anomaly who was successfully treated with imaging-guided sclerotherapy. This method of treatment for such a lesion has not been previously reported.
Case report A 23-year-old Chinese man presented with a 2-year history of a soft tissue mass on the anteromedial aspect of his right shin. The mass was not painful, and there was no past history of trauma or infection. On examination, there was a prominent mass over the tibia. It was soft, compressible, non-pulsatile and non-tender. The overlying skin, the rest of the right lower limb and the left lower limb were normal. In particular, no varicose vein was detected. Radiographs showed a well de®ned osteolytic groove in the mid-shaft of the right tibia (Figure 1). There was no periosteal reaction or cortical destruction. Magnetic resonance imaging (MRI) showed a 1.5 cm tubular lesion within the subcutaneous fat, communicating via a prominent intracortical nutrient canal with a dilated vessel in the adjacent medullary cavity of the tibia. These abnormal structures were T1 isointense, T2 hyperintense and enhanced markedly following Received 1 June 1999 and in revised form 11 August 1999, accepted 19 August 1999. Address correspondence to Professor W C G Peh, Department of Diagnostic Radiology, The University of Hong Kong, Room 406 Block K, Queen Mary Hospital, Hong Kong. 80
injection of intravenous (IV) gadopentetate dimeglumine (Gd-DTPA) (Figure 2). The surrounding calf muscles had a normal appearance on MRI. Antegrade right femoral arteriography showed normal vascular anatomy in the right lower leg. In particular, no intraosseous opaci®cation, neovascularity or early draining veins were present. A direct puncture of the subcutaneous portion of the lesion was performed using a 22 G Angiocath needle. Dark venous blood was aspirated and 5 ml of non-ionic contrast agent injected. Very slow ¯ow with virtual stasis of the injected contrast agent was noted (Figure 3). The direct venographic ®ndings corresponded to the subcutaneous and intraosseous components shown on MR images. Although the palpable mass was asymptomatic, the patient was concerned about its gradual enlargement and requested treatment. After a repeat direct venogram, 2 ml of absolute alcohol was injected into the subcutaneous component of the lesion without application of venous compression. The patient experienced transient pain lasting 2±3 min at the time of sclerotherapy, but was well thereafter. A compression bandage was applied to his right shin for 3 weeks. Repeat MRI 9 weeks post sclerotherapy showed a decrease in size of the soft tissue mass. Intravascular T1 and T2 hyperintense signal was present in the intraosseous and extraosseous components of the venous anomaly, consistent with thrombosis. MRI 5 months later showed complete resolution of the subcutaneous portion of the venous drainage anomaly. The intramedullary component was smaller than on the the preembolization MRI scan (Figure 4). The mass was not palpable and the patient was asymptomatic at the time of the last MRI. The British Journal of Radiology, January 2000
Case report: Treatment of tibial intraosseous venous drainage anomaly
Figure 2. Axial post Gd-DTPA, fat saturated, spin echo T1 weighted MR image of the mid tibia taken at the level of the palpable mass shows the subcutaneous (open arrow) and enlarged intramedullary (solid arrow) venous anomaly.
Figure 1. Lateral radiograph of the right mid tibia shows a prominent vascular groove in the diaphysis.
Discussion In 1997, Boutin et al [1] described six symptomatic patients who presented with pre-tibial varices in combination with an osteolytic defect on the anterior cortex of the tibia, a dilated intraosseous nutrient vein and an enlarged nutrient canal in the affected tibial diaphysis. The radiographic, MRI and venographic ®ndings in their cases were very similar to those of our patient, except for the absence of an anterior cortical defect and absence of calf muscle signal changes in the latter. As all their patients had painful symptoms and existing varices, Boutin et al postulated that centripetal transcortical venous ¯ow could be heightened secondary to venous insuf®ciency, venous hypertension, or both. As The British Journal of Radiology, January 2000
Figure 3. Lateral radiograph taken during direct venogram of the subcutaneous component shows opaci®cation of the intramedullary portion (arrow) of the venous anomaly.
none of their patients were asymptomatic, they were uncertain whether subcutaneous pre-tibial varices preceded the ossous ®ndings, or vice versa. The clinical and imaging features in our patient 81
W C G Peh, J W K Wong, W K Tso and E P Chien
Figure 4. Axial post Gd-DTPA, fat saturated, spin echo T1 weighted MR image of the mid tibia taken at the same level as Figure 2, obtained 7 months post sclerotherapy, shows resolution of the subcutaneous component of the lesion. The intramedullary portion (arrow) of the venous anomaly is reduced in size but remains patent.
would support the hypothesis that the intraosseous venous drainage anomaly was pre-existent. Our patient was relatively young, asymptomatic and had noticed a subcutaneous mass only in the 2 years prior to presentation. It is possible that the subcutaneous component of the venous anomaly developed secondary to increased pressure within the dilated intraosseous component, reversing the usual centripetal ¯ow direction of venous drainage in long bones [2]. MRI was useful in demonstrating the dilated
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intramedullary vein and its connection via the intracortical nutrient canal to the subcutaneous component of the lesion. Following sclerotherapy, MRI also served as a non-invasive method of monitoring the treatment response. Direct venography also con®rmed the connection between subcutaneous and intraosseous components of the venous anomaly. In our case, direct venography was useful in demonstrating very slow ¯ow of blood. This information prompted the decision to treat the patient using sclerotherapy rather than surgery. Boutin et al advocated that surgical ligation was safer, as the intraosseous tibial vein could not be compressed and the pre-tibial varices may be valveless and drained into the deep venous system [1]. In conclusion, by applying a meticulous diagnostic and interventional technique, the intraosseous venous drainage anomaly of the tibia can be safely and successfully treated using sclerotherapy.
Acknowledgment We thank Ms Alice Lau for her secretarial assistance.
References 1. Boutin RD, Sartoris DJ, Rose SC, Plecha EJ, Bundens WP, Haghighi P, et al. Intraosseous venous drainage anomaly in patients with pretibial varices: imaging ®ndings. Radiology 1997;202:751±7. 2. Trias A, Fery A. Cortical circulation of long bones. J Bone Joint Surg Am 1979;61:1052±9.
The British Journal of Radiology, January 2000
