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Kenji Inaba, MD FRCSC FACS
Assistant Professor of Surgery
Medical Director, SICU
LAC+USC Medical Center
SHUNTS
Indications
Temporary intravascular shunting is an important technique utilized to restore perfusion
distal to the site of an arterial injury. It is used for two clinical scenarios. First, in the
damage control setting, it allows rapid restoration of flow without the need for definitive
repair. The patient can then undergo physiologic normalization and when optimized,
return to the OR for definitive reconstruction of the injury. Under austere conditions
where either the operative conditions or technical surgical expertise are not optimal,
shunting allows temporary bridging of the patient until they can be transported to
definitive care. The other common indication is for combined orthopedic and vascular
injuries where shunting allows a window of opportunity for the orthopedic fixation to
occur without the risk of iatrogenic injury to the vascular repair. For venous injuries, in a
damage control situation where an attempt at venous reconstruction is planned, or, the
vein cannot be ligated, shunting may be used.
Technique
For combined othopedic injuries, close collaboration with the orthopedic team is
essential. The trauma team begins by exposing the vascular injury and isolating the
segment to be shunted. The ends of the artery are left intact as arterial wall proximal to
the ties securing the shunt will be sacrificed. If the injury is partial, but not amenable to
rapid primary repair and in need of shunting, the remaining bridge of wall can be cut to
facilitate shunt placement. Inflow and outflow clearance is performed with a balloon
catheter and local/systemic heparinization may be utilized if this is an isolated extremity
injury. The choice of shunt has not been demonstrated to impact outcomes. Care
should be taken to not damage the intima on insertion and the shunt should be inserted
so as to not cause injury from bowing. The shunt is secured using ties. One of the
ends may be secured to the tube itself to prevent migration. Reperfusion should be
checked and if required a fasciotomy may be performed at this point prior to orthopedic
fixation. Once the fracture has been stabilized, if the patient is able to undergo
definitive repair, the shunt is removed and the repair completed.
For patients undergoing shunting as a part of damage control, once perfusion is
restored, the patient is moved to the critical care setting to continue with resuscitation.
The patient does not require mandatory systemic heparinization while shunted.
Although there is no definitive upper time limit that the shunt can remain in place, once
the patient has been stabilized and is able to tolerate definitive vascular reconstruction,
the patient should undergo shunt removal.
REBOA-Resuscitative Endovascular Balloon Occlusion of the Aorta
Rationale
The REBOA technique consists of the placement of a purpose built occlusive balloon
through the Femoral Artery into the aorta, designed to occlude flow past the balloon.
This is not a new technique and has been described as far back as the Korean War. It
is also being used for the resuscitation of patients with ruptured abdominal aortic
aneurysms. This procedure can be performed in the ER or the OR under fluoroscopic
guidance. It is designed for patients with a subdiaphragmatic source of bleeding, where
balloon occlusion of the aorta would mitigate ongoing volume loss while preferentially
allowing perfusion of the heart and brain. This would facilitate volume loading and
ultimately prevent progression to arrest and allow a window for surgical or endovascular
stoppage of the source of blood loss. This is not a technique to be used in the arresting
patient. Arresting patients require a resuscitative thoracotomy so that direct cardiac
resuscitation can take place. Likewise, for bleeding sources above the diaphragm,
balloon occlusion would be of questionable value. The purpose of this segment of the
presentation will be to introduce the concept, demonstrate its potential and review the
current status of its use here in North America.
REFERENCES
1. Subramanian, A et al. A decade’s experience with temporary intravascular
shunts at a civilian level I trauma center. J Trauma. 2008; 65(2):316.
2. Taller, J et al. Temporary vascular shunts as initial treatment of proximal
extremity vascular injuries during combat operations. J Trauma. 2008;
65(3):595.
3. Stannard, A et al. Resuscitative Endovascular Balloon Occlusion of the Aorta
(REBOA) as an adjunct for hemorrhagic shock. J Trauma. 2011;71(6):18691872.