Venous Complications

Diagnostic Evaluation of Direct Venous Injury

During percutaneous interventions, a hematoma is most indicative of a complication from a venous injury. A hematoma may present as obvious swelling, but other more subtle signs and symptoms include access site pain, skin ecchymosis, continued bleeding through the puncture site, and hypotension. Duplex ultrasound of the localized hematoma is often necessary, especially if the hematoma is pulsatile, has a bruit over it, or is exquisitely tender, in order to rule out arterial pseudoaneurysm or AVF. Venous extravasation is generally not seen on ultrasound, but is instead seen as hematoma. Venous compression or thrombosis from the hematoma can also be seen.

A retroperitoneal hematoma is a clinical diagnosis. Retroperitoneal hematomas from femoral venous accesses have subtle physical exam findings but may convey a risk of morbidity and mortality if not identified. The retroperitoneal space accommodates a large amount of blood without tamponade from surrounding structures, and thus, complaints of back or lower abdominal pain, hypotension, tachycardia, and oliguria should raise suspicion to diagnose and manage urgently. Patients should promptly be considered for a CT scan. By using contrast, an abdominal and pelvic CT scan can readily identify arterial or venous injury and resulting hematoma, pseudoaneurysm, or extravasation ( Fig. 53.2 ).

Venous injuries during open surgical approaches are often diagnosed by direct visualization. However, if clinically occult, computed tomography and magnetic resonance angiography in the delayed phase can provide a diagnosis.

Management of Direct Venous Injury

Venous access site injury during a percutaneous intervention often results in hematoma formation. Early recognition limits significant morbidity. Although often self-limiting, pressure over the puncture site is recommended. The area should be marked to evaluate for any expansion and be serially monitored. Monitoring serial hemoglobin levels and prolonging bedrest is recommended. Most hematomas resolve within a few weeks. Hematoma size varies, and if skin compromise is evident, evacuation and debridement of the affected area is necessary.

In coagulopathic patients, however, aggressive resuscitation with blood products may be required, especially if a retroperitoneal hematoma is suspected. Although most retroperitoneal hematomas can be managed with resuscitation, bedrest, and monitoring serial hematocrit levels, hemodynamic instability, ongoing blood loss, and neurologic deficits due to compression of adjacent nerves are indications for further imaging and possibly open surgical exploration or endovascular treatment. Complications from venous intervention remote from the access area are now recognized as increasingly common. Treatment of these complications is an evolving area of vascular surgery and is individually determined on a symptomatic basis. With larger covered stents now available, the capability of placing these in the central veins exists, and may be a safer option than open repair, especially in patients with significant comorbidities.

Venous injury during open surgical procedures, such as an iliac vein injury during an aortobifemoral bypass or spine exposure, ranges from small adventitial hematomas to complete transections. Small injuries often are managed conservatively with direct pressure. However, tears and lacerations can be repaired with 5-0, 6-0, or 7-0 monofilament sutures as appropriate for vein size. Proximal and distal control is often not necessary but can be done gently with sponge sticks if required. Encircling and clamping veins to assist in repairing injuries frequently causes additional trauma and bleeding as small branches may be sheared and large soft veins are susceptible to clamp trauma. In general, when severely injured and resulting in hemodynamic instability, the brachiocephalic, internal jugular, subclavian, and extremity veins can be ligated, especially if the contralateral side is patent. Open repair, however, is generally preferred. Vena caval, femoral, brachiocephalic, or subclavian/axillary vein injuries can be closed with a transverse primary repair with 4-0 or 5-0 monofilament suture if there is no significant loss of vein caliber. With a loss of caliber, it is necessary to replace this lost segment, usually with lateral venorrhaphy and a bovine pericardial patch in the IVC or vein patch in smaller vessels, to avoid tension or stricture. Large abdominal veins such as the renal or superior mesenteric veins should be repaired. However, in the context of hemodynamic instability, vein ligation may be indicated.

For vena caval injuries, endovascular repair options include balloon occlusion or control, and the use of a covered stent. These interventions are usually performed in a hybrid OR. Balloon occlusion with large, low-pressure balloons from above and below the injury, either inserted percutaneously from the jugular and femoral sites or inserted through the injury, can slow down blood loss and may allow enough visualization for an open repair. If the injury is being managed percutaneously, there are reports of covered stent grafts in the IVC. These are difficult to size, as the injured cava may have ill-defined walls and the size of the tear may be difficult to appreciate on CT or venogram. In addition, there may be spasm of the IVC or underfilling from blood loss that leads to placement of cuffs that could embolize once the cava is fully expanded.

In the event of a posterior vena caval injury, this difficult problem can possibly be managed by control of the cava and opening the cava on the anterior surface to visualize the posterior tear. This can then be repaired from inside the cava and the anterior exposure site can be primarily closed in a transverse manner. If there is a significant loss of calibre in any of these large veins, and the patient is hemodynamically stable, the injured section of vein can be replaced with a prosthetic graft, usually 20–24 mm in diameter, or a spiral vein graft if time allows. If a prosthetic graft is used, consideration should be given to prolonged systemic anticoagulation, a distal arteriovenous fistula, or both to optimize patency. Severe venous injuries, especially in the infra- or suprahepatic regions of the IVC, carry a very high morbidity and mortality.

Arteriovenous Fistulas

An arteriovenous fistula (AVF), a direct communication between an artery and a vein, often can occur after penetrating trauma, where ongoing bleeding from an artery decompresses into an adjacent venous injury ( Fig. 53.3 ). With increasing numbers of invasive percutaneous procedures, vascular cannulation accounts for most AVFs. The incidence ranges from 0.0006% to 0.88%. Total knee replacements, lumbar disc surgery, ^, and percutaneous biopsies, such as in transplant kidneys, may also result in AVFs.