Clinical Presentation of External Iliac Arteriovenous Fistula

Penetrating lower abdominal trauma frequently causes complex vascular disruptions that demand rapid clinical evaluation. An external iliac arteriovenous fistula represents an uncommon yet life-threatening vascular lesion resulting from sharp penetrating trauma. In this setting, an abnormal communication forms directly between the high-pressure external iliac artery and vein. Consequently, arterial blood rapidly shunts into the venous circulation, bypassing the lower extremity capillary bed. While many trauma patients present with profound shock, others maintain normal blood pressure upon hospital arrival. For example, a 47-year-old male recently presented with a lower abdominal stab wound while remaining hemodynamically stable. However, physical examination alone cannot reliably detect deep retroperitoneal vascular injuries. Therefore, clinicians must maintain a high index of suspicion whenever penetrating trauma crosses the pelvis. Untreated high-volume arteriovenous shunting causes severe downstream venous hypertension and progressive high-output heart failure. Additionally, arterial steal syndrome can severely compromise peripheral limb perfusion. Early recognition allows the trauma team to coordinate specialized interventions before catastrophic physiological decompensation ensues. Prompt vascular imaging remains vital for preventing intraoperative hemorrhage.

Diagnostic Evaluation and Angiographic Imaging

Contrast-enhanced computed tomography angiography represents the diagnostic cornerstone for evaluating stable penetrating abdominal injuries. In modern trauma resuscitation, hemodynamic stability creates a critical opportunity to obtain detailed cross-sectional imaging. Specifically, multiphase computed tomography scans rapidly detect retroperitoneal hematomas, active arterial extravasation, and unsuspected organ injuries. In this case, an urgent scan revealed hemoperitoneum and a fistula connecting the left external iliac vessels. Furthermore, imaging clearly demonstrated premature contrast enhancement within the external iliac vein during the early arterial phase. This rapid venous filling provides unmistakable radiological evidence of an acute arteriovenous fistula. Radiologists must scrutinize pelvic vessels carefully, because localized puncture injuries can generate deceptively small retroperitoneal hematomas. In addition, concurrent intraperitoneal free fluid or pneumoperitoneum frequently signals penetrating intestinal disruption. Without timely contrast imaging, surgical teams might proceed directly to open surgery without recognizing retroperitoneal vascular involvement. Consequently, early imaging changes trauma management by allowing clinicians to design a sequential, minimally invasive intervention before opening the abdomen. This strategic roadmap significantly diminishes the danger of unexpected massive hemorrhage during subsequent exploratory laparotomy.

Endovascular Covered Stenting Prior to Laparotomy

Traditional surgical doctrine dictates urgent exploratory laparotomy for penetrating abdominal injuries with active bleeding. However, dissecting a tense retroperitoneal hematoma in the pelvis presents severe operational challenges. Open exposure within pelvic Zone 3 frequently releases local tamponade, causing torrential bleeding from thin-walled iliac veins. In addition, obtaining proximal and distal vascular control deep within the pelvis demands extensive surgical exposure. Therefore, deploying an endovascular covered stent prior to laparotomy offers immense strategic advantages in hemodynamically stable patients. Interventional radiologists introduce a covered stent-graft via retrograde femoral arterial access under fluoroscopic control. By deploying the endograft precisely across the arterial tear, operators exclude the arteriovenous fistula immediately. This prompt occlusion halts pathological blood shunting and secures arterial hemostasis at its precise anatomical source. Furthermore, endovascular intervention eliminates the high-pressure hemodynamic driver feeding the retroperitoneal hematoma. As a result, surgical teams encounter a completely stable, non-bleeding retroperitoneal space during the subsequent laparotomy. Surgeons avoid blind vascular clamping in flooded operative fields, which dramatically reduces iatrogenic neurovascular damage. Thus, pre-laparotomy endovascular repair establishes early vascular control and transforms high-risk trauma into a controlled surgical procedure.

Operative Strategy for Associated Intestinal Perforations

Although endovascular techniques achieve prompt vascular exclusion, penetrating abdominal trauma rarely spares adjacent intra-abdominal organs. Sharp stab wounds crossing the abdominal cavity frequently injure the small intestine, colon, or mesentery. In the presented case, surgeons immediately transferred the patient to the operating room after successful stent placement. During subsequent exploratory laparotomy, the team identified hemoperitoneum alongside an omental laceration and a discrete small bowel perforation. Surgeons promptly performed enterorrhaphy and excised the injured omentum. Crucially, inspection of the retroperitoneum revealed an intact hematoma without active expansion, pulsatility, or bleeding. Because the endovascular stent had already isolated the external iliac injury, surgeons deliberately avoided unroofing the retroperitoneum. Violating an intact pelvic hematoma often converts a stable situation into torrential retroperitoneal venous hemorrhage. Instead, the surgical team focused entirely on meticulous bowel repair and extensive peritoneal lavage. The patient recovered rapidly without complications and achieved discharge on postoperative day six. This favorable course proves that combining endovascular hemostasis with selective laparotomy resolves both vascular and visceral injuries effectively. Such disciplined surgical restraint prevents lethal iatrogenic vascular catastrophe.

Postoperative Complications, Long-Term Durability, and Trauma Protocols

Despite remarkable immediate technical success, deploying covered stents in penetrating trauma introduces notable clinical dilemmas. Foremost among these issues is the heightened threat of endograft sepsis. Penetrating abdominal injuries often cause intestinal perforation, which exposes nearby intravascular hardware to bacterial contamination. Introducing a prosthetic implant into a contaminated peritoneal cavity requires aggressive broad-spectrum antibiotic prophylaxis. Additionally, traumatic vascular disruptions predominantly occur in young, active patients whose arteries undergo repetitive biomechanical strain. Iliac vessels experience significant mechanical flexion during walking, sitting, and running. Consequently, covered stents placed across the pelvic brim risk mechanical fatigue, fabric disruption, migration, and endoleak development over time. Furthermore, neointimal hyperplasia can gradually narrow the stent lumen, leading to delayed thrombosis. Therefore, trauma specialists must establish meticulous long-term outpatient follow-up. Patients require serial duplex ultrasonography and periodic computed tomography angiography to verify stent integrity and vessel patency. In emergency centers across India, incorporating early hybrid workflows will significantly modernize trauma care. Developing standardized protocols for hybrid endovascular and open surgical management ensures optimal patient survival while preserving institutional resources. These principles guide modern vascular trauma care.

Frequently Asked Questions

Why is endovascular repair preferred over open surgery for traumatic external iliac arteriovenous fistula?

Traumatic pelvic vascular injuries lie deep within the retroperitoneal space, surrounded by dense connective tissue and fragile veins. Direct surgical dissection into a tense retroperitoneal hematoma frequently releases natural tamponade and triggers severe venous hemorrhage. In contrast, endovascular covered stenting achieves immediate arterial exclusion without disrupting surrounding retroperitoneal structures. Consequently, this minimally invasive approach minimizes operative blood loss and avoids blind pelvic clamping. In addition, it prevents inadvertent venous tearing and reduces perioperative surgical morbidity.

When can trauma surgeons avoid exploring a retroperitoneal hematoma during laparotomy?

Surgeons can safely leave a Zone 3 pelvic retroperitoneal hematoma unexplored when it remains stable. It must appear non-expanding, non-pulsatile, and successfully controlled by prior endovascular intervention. Opening a stable pelvic hematoma risks releasing tamponade and provoking unmanageable venous bleeding. Therefore, if pre-procedural covered stenting has already isolated the underlying vascular laceration, surgeons should avoid opening the retroperitoneum. Instead, clinical teams should dedicate their operative time to repairing concomitant hollow viscus perforations and addressing intraperitoneal contamination.

What are the primary long-term concerns following covered stent placement for traumatic vascular injuries?

The primary long-term concerns include endograft infection, device migration, stent fracture, and delayed vascular occlusion. Because penetrating trauma often involves hollow viscus injury, bacteria can seed prosthetic intravascular materials. Furthermore, the external iliac artery undergoes repetitive mechanical flexion during hip motion, creating substantial mechanical strain on metallic stents. Consequently, patients require extended post-discharge clinical monitoring with serial duplex ultrasound scans. These non-invasive studies confirm lasting vessel patency and detect late structural stent failures early.

Disclaimer: This content is for informational and educational purposes only... Refer to the latest local and national guidelines for clinical practice.

References

Kai T et al. External Iliac Arteriovenous Fistula Caused by Stab Wound. Clin Case Rep. 2026 Oct undefined. doi: 10.1002/ccr3.73691. PMID: 42859726.

Waller CJ, et al. Role of Endovascular Stenting in Patients with Traumatic Iliac Artery Injury. J Am Coll Surg. 2023;236(5):753-759.

Ambler GK, et al. Endovascular treatment of traumatic vascular injuries. Br J Surg. 2021;108(4):370-378.