Residency · Residency · Vascular Surgery
Iatrogenic Vascular Injuries and Access Site Complications
Overview
Iatrogenic vascular injuries represent the most common type of vascular injuries encountered in civilian medical practice. These injuries typically arise as a consequence of diagnostic or therapeutic catheterization, surgical procedures, central line placements, and other invasive interventions. The frequency of such injuries has increased in parallel with the growing use of endovascular and percutaneous techniques. While most iatrogenic vascular injuries can be effectively managed using minimally invasive methods, a subset requires open surgical repair to achieve definitive treatment.
Femoral Access Complications
Femoral Pseudoaneurysm
The femoral pseudoaneurysm is the most frequent complication following femoral artery catheterization, occurring in approximately 0.5% to 8% of cases. It develops when the arterial puncture site fails to seal properly, resulting in a contained, pulsatile hematoma that maintains communication with the arterial lumen. Several risk factors predispose patients to pseudoaneurysm formation, including anticoagulation or antiplatelet therapy, use of large sheath sizes, low puncture sites involving the superficial femoral or profunda femoris arteries, obesity, aortic procedures, and multiple arterial punctures.
Clinically, patients often present with a pulsatile mass in the groin, accompanied by a bruit and localized pain. Duplex ultrasound is the diagnostic modality of choice, revealing the characteristic "yin-yang" sign that reflects swirling blood flow within the pseudoaneurysm sac, and a "to-and-fro" spectral Doppler waveform in the neck connecting the sac to the artery. It is important to differentiate pseudoaneurysms from simple hematomas, which lack internal flow, and from arteriovenous (AV) fistulas, which demonstrate high-velocity flow from artery to vein.
Management strategies depend on the size and symptoms of the pseudoaneurysm. Small pseudoaneurysms less than 2 cm in diameter in patients not on anticoagulation may thrombose spontaneously and can be observed. Ultrasound-guided compression repair (UGCR) involves applying probe pressure over the pseudoaneurysm neck for 20 to 30 minutes, achieving success rates between 60% and 90% in patients off anticoagulation. However, this method is often painful, time-consuming, and requires sedation, leading to its replacement by ultrasound-guided thrombin injection (UGTI).
UGTI is now considered the gold standard for treating femoral pseudoaneurysms. This technique involves injecting bovine or human thrombin (typically 100 to 1000 units) directly into the pseudoaneurysm sac under ultrasound guidance, avoiding injection into the neck or native artery to prevent thrombosis. UGTI has a success rate exceeding 95%, with rapid thrombosis occurring within seconds. Potential complications include distal embolization (less than 1%), allergic reactions to bovine thrombin, and infection. It is contraindicated in cases with a very wide neck due to the risk of arterial thrombosis or in the presence of infection. For pseudoaneurysms unsuitable for thrombin injection, covered stents or coil embolization may be employed. Surgical repair is reserved for expanding or ruptured pseudoaneurysms, infected lesions, failed percutaneous treatments, or associated AV fistulas requiring correction. Surgical intervention typically involves direct arterial repair using sutures or patch angioplasty.
<image>Duplex ultrasound images showing a femoral pseudoaneurysm with the characteristic "yin-yang" swirling flow pattern within the sac and "to-and-fro" spectral Doppler waveform in the communicating neck</image>
Femoral Arteriovenous Fistula (Iatrogenic)
An iatrogenic femoral arteriovenous fistula occurs when an arterial puncture traverses both the femoral artery and the adjacent femoral vein, creating an abnormal connection. This complication arises in approximately 0.2% to 1.5% of femoral catheterizations. Patients may present with a palpable thrill, a continuous bruit often described as a "machinery murmur," and leg swelling. Duplex ultrasound confirms the diagnosis by demonstrating high-velocity turbulent flow from the artery into the vein and an arterialized venous waveform.
Management depends on symptomatology and fistula size. Small, asymptomatic fistulas can be observed as many close spontaneously. Symptomatic or enlarging fistulas require intervention, which may include placement of a covered stent across the fistula site within the artery or surgical repair involving ligation of the fistula and arterial reconstruction. Ultrasound-guided compression is rarely effective for this condition.
Retroperitoneal Hemorrhage
Retroperitoneal hemorrhage is a life-threatening complication that arises from a high femoral arterial puncture performed above the inguinal ligament. In this scenario, bleeding tracks into the retroperitoneal space, allowing large volumes of blood to accumulate without obvious external signs. Risk factors include puncture above the inguinal ligament, anticoagulation, use of large sheaths, and failed closure devices.
Clinically, patients present with flank, back, or abdominal pain accompanied by hypotension, tachycardia, a falling hemoglobin level, and sometimes groin ecchymosis. Diagnosis is typically confirmed by emergent contrast-enhanced computed tomography (CT). In some cases, the diagnosis is made based on hemodynamic instability alone. Management involves aggressive resuscitation with blood products and reversal of anticoagulation. If the puncture site is identifiable angiographically, covered stent placement or balloon tamponade can be employed. Surgical exploration and repair are reserved for patients who remain hemodynamically unstable despite resuscitation or when endovascular measures fail.
<image>CT angiography showing a large retroperitoneal hematoma following femoral catheterization with active contrast extravasation from a high femoral arterial puncture site above the inguinal ligament</image>
Access Site Thrombosis/Occlusion
Thrombosis or occlusion at the arterial access site may result from arterial dissection, thrombosis, or embolization. Risk factors include small artery diameter, underlying atherosclerotic disease, use of large sheaths, and prolonged procedural times. Patients typically present with signs of acute limb ischemia. Treatment involves surgical thromboembolectomy or catheter-directed thrombolysis combined with angioplasty. Preventative measures include using the smallest sheath size adequate for the procedure, employing ultrasound-guided access, and adhering to careful technique.
Closure Device Complications
Complications related to vascular closure devices vary depending on the device type. Suture-based devices such as ProGlide and Perclose can cause vessel stenosis, failed closure, or suture entanglement. Plug-based devices like Angioseal and Mynx carry risks of plug embolization, infection, and vessel occlusion. Clip-based devices such as StarClose may lead to vessel narrowing or clip migration. The infection rate associated with closure devices is approximately 0.3% to 0.5%, occasionally necessitating surgical explantation and repair. Closure device failure requiring surgical intervention occurs in 1% to 3% of cases.
Radial Artery Complications
Radial Artery Occlusion
Radial artery occlusion is the most common complication of transradial access, occurring in 2% to 10% of cases. It is usually asymptomatic due to the dual blood supply of the hand via the ulnar artery and the palmar arch. Risk factors include a small radial artery diameter, prolonged compression, and a large sheath-to-artery ratio. Prevention strategies focus on maintaining "patent hemostasis," which involves preserving antegrade flow during compression, using smaller sheaths, and administering anticoagulation. Treatment is generally conservative, as the radial artery may recanalize spontaneously.
Radial Artery Pseudoaneurysm
Radial artery pseudoaneurysms are rare and typically occur at the puncture site. Management includes ultrasound-guided compression or thrombin injection, with surgical repair reserved for refractory cases.
Radial Artery Spasm
Radial artery spasm is a common occurrence during catheterization and can impede catheter advancement or removal. Treatment involves intra-arterial vasodilators such as nitroglycerin or verapamil, application of warm compresses, and sedation. Prophylactic administration of vasodilators, often as a radial artery cocktail combining nitroglycerin, verapamil, and heparin, helps reduce the incidence of spasm.
Central Venous Catheter Complications
Arterial Puncture
Inadvertent arterial puncture during central line placement can involve the carotid or subclavian arteries. If a small-bore needle is used, the needle should be withdrawn and pressure applied, as this is usually benign. However, if a large-bore catheter is inadvertently placed in an artery, it must not be removed at the bedside. The catheter should be left in place, and vascular surgery consultation obtained for controlled removal in the operating room with surgical repair or endovascular covered stent placement. Uncontrolled removal risks severe hemorrhage, stroke (if carotid artery involved), hemothorax (if subclavian artery involved), or pseudoaneurysm formation.
Guidewire/Catheter Embolization
Shearing of guidewires or catheter fragments can lead to embolization into central veins, the heart, or pulmonary arteries. Diagnosis is made by chest X-ray or fluoroscopy. Treatment involves percutaneous snare retrieval using loop or gooseneck snares, with success rates exceeding 90% when performed by experienced interventional teams.
Pneumothorax
Pneumothorax is a known complication of subclavian or misdirected internal jugular vein access. Diagnosis is confirmed by post-procedure chest X-ray and clinical signs such as dyspnea and decreased breath sounds. Small pneumothoraces may be managed conservatively with observation or aspiration, while large or symptomatic cases require chest tube placement.
Air Embolism
Air embolism can occur during catheter insertion, hub disconnection, or catheter removal if air enters the venous system. Prevention includes placing the patient in the Trendelenburg position and performing the Valsalva maneuver during access. Treatment involves positioning the patient in the left lateral decubitus and Trendelenburg positions, aspirating air from the catheter if still in place, and providing supportive care.
Surgical Iatrogenic Injuries
Intraoperative Arterial Injury
Arterial injuries can occur during any surgery near major vessels. Common scenarios include laparoscopic trocar injury to iliac vessels, orthopedic surgery involving the femoral or popliteal arteries, spine surgery affecting the aorta, iliac vessels, or inferior vena cava, and abdominal surgery involving mesenteric vessels. Recognition is based on unexpected bleeding, hematoma formation, or hemodynamic instability. Management depends on the injury's location and severity and may involve direct repair, graft interposition, or endovascular covered stent placement.
Lymphatic Injury
Groin dissections can damage lymphatic channels, leading to lymphocele formation or lymphatic leaks. Treatment options include compression, wound care, aspiration or drainage of lymphoceles, surgical ligation of leaking lymphatics, and sclerotherapy. Prevention relies on meticulous surgical technique and ligation of lymphatic vessels encountered during femoral exposure.
Nerve Injury
Nerve injuries may occur during groin surgery (femoral nerve), subclavian or internal jugular vein cannulation (phrenic nerve), or axillary and subclavian procedures (brachial plexus). Most nerve injuries are neuropraxias that recover over time. It is important to document any deficits and monitor recovery.
<image>Angiographic image demonstrating ultrasound-guided thrombin injection into a femoral pseudoaneurysm showing the needle tip within the sac and post-injection thrombosis with cessation of flow on completion duplex</image>
Prevention Strategies
Ultrasound-guided vascular access significantly reduces complications for both arterial and venous access and should be considered the standard of care. The micropuncture technique, which uses a 21-gauge needle and 4 French initial access sheath, minimizes vessel trauma. Fluoroscopic guidance aids in wire advancement and catheter positioning. Selecting the appropriate puncture site is critical; fluoroscopic identification of the femoral head allows puncture at the mid-femoral head level, targeting the common femoral artery while avoiding punctures above the inguinal ligament or below the bifurcation. Using the smallest sheath size adequate for the procedure further reduces vessel injury. Closure device selection should be tailored to vessel size and clinical context. Finally, team training through simulation, checklists, and institutional protocols plays a vital role in minimizing procedural complications.
Clinical Pearls
A pulsatile groin mass following catheterization should be presumed to be a pseudoaneurysm until proven otherwise, with duplex ultrasound serving as the initial diagnostic tool. Ultrasound-guided thrombin injection achieves a success rate exceeding 95% for pseudoaneurysms and has largely supplanted compression repair and surgery for uncomplicated cases. If a large-bore catheter is inadvertently placed in the carotid artery, it should never be removed at the bedside; instead, it must be left in place with urgent vascular surgery consultation for controlled extraction. Retroperitoneal hemorrhage is a "silent killer" and should be suspected in any post-catheterization patient presenting with unexplained hypotension, tachycardia, or back or flank pain. Ultrasound-guided vascular access reduces complication rates by 50% to 80% compared to landmark-based techniques and represents the single most important prevention strategy. Maintaining patent hemostasis by preserving antegrade flow during radial artery compression dramatically reduces radial artery occlusion rates. Every vascular access complication provides a valuable learning opportunity, and institutions should track and review these events as part of quality improvement initiatives.
References
- Defined Category Definitions for Peri-Operative Outcomes. Writing Group for the SVS. J Vasc Surg. 2020.
- Stone PA, et al. Pseudoaneurysm of the femoral artery: modern approach. Am Surg. 2014;80(12):1268-1271.
- Tsetis D. Endovascular treatment of complications of femoral arterial access. Cardiovasc Intervent Radiol. 2010;33(3):457-468.
- Seto AH, et al. Real-time ultrasound guidance facilitates femoral arterial access and reduces vascular complications. JACC Cardiovasc Interv. 2010;3(7):751-758.
- Brannam L, et al. Emergency nurses' utilization of ultrasound guidance for placement of peripheral intravenous lines in difficult-access patients. Acad Emerg Med. 2004;11(12):1361-1363.
