Endovascular management of a traumatic lower extremity arteriovenous fistula following a machete injury

Abstract

Traumatic arteriovenous fistulas (AVFs) are uncommon and can be associated with significant morbidity. Given their complex anatomy, diagnosis and treatment can be challenging. We present the successful management of a patient with a 7-year history of a lower extremity traumatic AVF, which led to chronic venous insufficiency and nonhealing venous ulcers. This case highlights how precise anatomic definition enabled targeted endovascular repair of a complex AVF.

Traumatic arteriovenous fistulas (AVFs), though uncommon, are an important cause of long-term morbidity after penetrating vascular injuries. They most commonly occur after penetrating trauma, such as gunshot or stab wounds, but have also been reported after blunt trauma and iatrogenic injuries.^1,2 Despite their rarity, traumatic AVFs can lead to substantial morbidity, including limb swelling, pain, chronic venous insufficiency, ulceration, and, in advanced cases, high-output cardiac failure.³ Historically, open surgical repair was the mainstay of treatment.⁴ However, delayed presentations often present unique technical challenges, as chronic AVFs are associated with extensive collateralization, vessel dilation, and surrounding fibrosis, which increase operative complexity and morbidity.^5,6 Endovascular therapy has therefore provided less invasive alternatives to open repair. Covered stent placement enables precise exclusion of the fistula while preserving arterial patency and minimizing surgical trauma.^7,8 In addition, multiple reports have demonstrated the safety and efficacy of endovascular repair in both acute and chronic settings, particularly for anatomically complex lesions or patients deemed high risk for open surgery.⁹ We report the successful endovascular management of a patient with a chronic lower extremity AVF caused by a machete injury, complicated by longstanding venous insufficiency and nonhealing ulcers. Informed consent for the publication of this case was obtained.

Case report

A 32-year-old man with a history of traumatic right lower extremity injury from a machete stabbing, who had previously undergone a nonspecified surgical intervention in Guatemala (with no medical records available), presented to the emergency department with a 7-year history of right lower extremity edema and nonhealing wounds. The patient reported that the wounds had been present for several years and had not improved with compression therapy. On examination, he had a normal vascular examination with palpable distal pulses. However, there was a right lower extremity wound above the medial malleolus associated with hyperpigmentation and dermal fibrosis. Based on the presence of an active ulcer, this was classified as Classification, Etiology, Anatomy, Pathophysiology class 6 chronic venous disease.

A computed tomography angiogram (CTA) revealed a right lower extremity AVF, likely arising from the anterior tibial artery (ATA) and the tibioperoneal trunk (TPT) (Fig 1). A vascular ultrasound examination was also performed, which confirmed these findings. Given the patient's symptoms, we proceeded with an initial right lower extremity angiogram to further delineate the AVF anatomy.

Fig 1.

Admission computed tomography angiography (CTA) of the lower extremities demonstrating an arteriovenous fistula arising from the anterior tibial artery and the tibioperoneal trunk (arrows).

Operative technique

Via left common femoral artery access, a right lower extremity angiogram was performed, revealing a complex AVF. An extensive evaluation was conducted, individually interrogating each vessel with and without balloon occlusion using a 4-mm balloon for the tibial vessels and a 6-mm balloon for the popliteal artery (Armada; Abbott Medical), which confirmed two AVFs—one arising from the ATA, and another from the TPT (Fig 2).

Fig 2.

A, Intraoperative angiogram demonstrating a complex arteriovenous fistula arising from the anterior tibial artery (solid arrow) and the tibioperoneal trunk (dashed arrow). B, Intraoperative angiogram demonstrating the arteriovenous fistula between the anterior tibial artery and vein. C, Intraoperative angiogram further delineating the arteriovenous fistula between the anterior tibial artery and vein.

A discussion was then had with the patient to review the available treatment options, including open repair, which would be challenging due to an increased risk of bleeding; endovascular repair, with the possibility of requiring an open procedure in the future; and nonoperative management, which carried the risk of persistent symptoms and recurrent ulceration. Importantly, we discussed that the ATA would have to be sacrificed, through ligation or embolization, regardless, as preservation would not be possible with either an open or endovascular approach. After this discussion, the patient elected to proceed with endovascular treatment. The patient had two known AVFs, and both the inflow and outflow of each fistula needed to be addressed to prevent persistent shunting and ongoing venous hypertension.

The patient was taken to the operating room, where contralateral femoral artery access and retrograde dorsalis pedis access were obtained. The proximal anterior tibial vein was selected from above, transarterially through the AVF, and was embolized using 4-mm and 8-mm Amplatzer plugs (AVP; Abbott), whereas the ATA was embolized with a 6-mm Amplatzer plug (AVP; Abbott) and a 10 cm × 6 mm Azur coil (Terumo) delivered from the retrograde pedal access. Given that the below-knee popliteal artery measured 6.5 mm in diameter and the proximal TPT measured 6.0 mm, a 7 mm × 5 cm Viabahn stent graft (W. L. Gore & Associates) was then deployed from the below-knee popliteal artery into the TPT, successfully covering the ATA inflow into the ATA/vein AVF, as well as the TPT AVF. Completion angiography demonstrated successful exclusion of the AVF, with a patent stent and two-vessel runoff to the foot (Fig 3). The patient had an intact pedal arch with retrograde filling of the dorsalis pedis seen.

Fig 3.

A, Intraoperative angiogram demonstrating the arteriovenous fistula. B, Successful deployment of the Viabahn stent graft. C, Completion angiogram showing resolution of the arteriovenous fistula with a patent stent and two-vessel runoff to the foot.

The patient was discharged directly from the recovery room with a plan to continue dual antiplatelet therapy (Clopidogrel 75 mg daily as well as aspirin 81 mg daily) for 6 months. At 3-month follow-up, the patient's wounds had healed, and his duplex ultrasound examination demonstrated a patent stent with no signs of residual AVF and a normal ankle-brachial index.

Discussion

Traumatic AVFs are uncommon sequelae of penetrating vascular injuries but can result in substantial long-term morbidity if not recognized and treated. Most traumatic AVFs occur after penetrating trauma, such as gunshot or stab wounds, although other causes have also been reported.^1,2 Despite their rarity, they can lead to progressive venous hypertension, limb swelling, pain, skin hyperpigmentation, and chronic ulceration. Our case illustrates the chronic complications that may develop in these patients.

Accurate diagnosis of traumatic AVFs is critical to guide management. Duplex ultrasound examination provides a rapid, noninvasive assessment and is useful for detecting hemodynamic changes suggestive of AVF.¹⁰ This is typically manifested by turbulent, high-velocity flow with spectral broadening at the fistula site, along with an arterialized, high-velocity waveform in dilated, thick-walled draining veins and continuous flow without respiratory variation.¹¹ However, given its high sensitivity and specificity, CTA has become the diagnostic study of choice.^12,13 In complex cases, as in our patient, CTA combined with catheter-based angiography ensures a precise anatomic definition allowing for a tailored treatment approach.

Historically, open surgical repair was considered the gold standard for treatment.⁴ However, delayed presentations are particularly challenging due to extensive collateralization and perivascular fibrosis, all of which increase technical complexity and operative risk. In such cases, surgical repair carries an increased risk of bleeding, nerve injury, and morbidity.

Endovascular techniques have increasingly emerged as minimally invasive and effective alternatives. Covered stent placement allows precise exclusion of the fistula while maintaining arterial patency and reducing operative trauma.^7,8 Several studies have demonstrated favorable outcomes with endovascular repair in both acute and chronic traumatic AVFs, particularly in anatomically complex lesions or in patients at high risk for open surgery.7, 8, 9

In this patient, multimodal imaging with CTA, duplex ultrasound examination, and diagnostic angiography was essential for defining the AVF anatomy and enabling a precise endovascular approach. Because we were unable to access the ATA from an antegrade approach, retrograde dorsalis pedis access was required to embolize the ATA and completely exclude the AVF.

Despite the favorable short-term outcome, the long-term durability of endovascular repair in the tibial and popliteal segments, particularly in young patients, remains a concern.¹⁴ Lifelong surveillance with duplex ultrasound examination is essential, and patients should be counseled regarding the potential need for reintervention or future open reconstruction.

Our case highlights the importance of maintaining a high index of suspicion for AVF in patients with chronic venous insufficiency and a history of extremity trauma. It also emphasizes the role of multimodality imaging to confirm the AVF anatomy and the feasibility of performing an endovascular approach. Although open repair remains an option in selected cases, endovascular therapy provides a safe and effective alternative, even in delayed presentations. Careful patient selection, multidisciplinary evaluation, and long-term surveillance are essential to ensure durable outcomes, and to anticipate the need for future reintervention or open reconstruction if needed.

Conclusions

This unique case describes a traumatic lower extremity AVF resulting in chronic venous insufficiency and nonhealing wounds. It highlights the successful multidisciplinary management of a complex AVF using an endovascular approach to delineate the anatomy and perform definitive treatment. Although endovascular approaches are associated with reduced morbidity, careful patient selection based on anatomical characteristics is critical, with the understanding that open vascular reconstruction may be required in the future.

Funding

None.

Disclosures

None.