Discussion
The choice of a resuscitative thoracotomy would be controversial in the modern era, particularly in a patient with a peripheral rather than a thoracic vascular injury. Rapid insertion of a REBOA device, rapid blood transfusion, and application of a new pressure dressing on the right axilla would have been the preferred management in some centers.1 In this patient with no blood pressure during the latter stages of transport and no palpable pulse in the trauma room, a cardiopulmonary arrest appeared imminent. For this reason, a resuscitative thoracotomy with cross-clamping of the descending thoracic aorta was chosen.2
Ligation of the right axillary vein rather than insertion of a temporary intraluminal shunt was another controversial choice in management of this patient. Significant injuries to the axillary vein, however, have been managed with ligation rather than complex reconstruction for many years in urban trauma centers. Although edema of the ipsilateral upper extremity may occur in the hospital, it essentially always resolves after several days of elevation. This is related to the extensive venous collateral network around the axilla as follows: (1) venae comitantes of the brachial artery; (2) profunda brachii, posterior humeral circumflex, and circumflex scapular venae comitantes; (3) subscapular and suprascapular veins; and (4) external jugular vein.3
The history of the use of temporary intraluminal vascular shunts has been summarized in several publications during the past decade.4 5 While there are multiple possible indications for insertion of a shunt (box 1), the majority are inserted in patients with Gustilo IIIC open fractures or in those with a significant vascular injury and the need for ‘damage control’.
Box 1Possible indications for insertion of a temporary vascular shunt after trauma*
Complex repair of the internal carotid artery in zone III of the neck.
Need for distal perfusion as a complex revascularization is performed.
Gustilo IIIC open fracture of an extremity.
Perfusion of an amputated part of an upper extremity prior to replantation.
‘Damage control’ for the patient with near-exsanguination from a peripheral vascular injury.
‘Damage control’ for the patient with multiple intra-abdominal injuries including an abdominal vascular injury.
‘Damage control’ for the patient with a cervical, truncal, or peripheral vascular injury and a surgical team with an overwhelming number of casualties, limited resources, or limited experience with vascular injuries (military triage).
*Adapted from Feliciano and Subramanian.5
The largest possible shunt should be inserted into the transected or debrided ends of the vessel. In the largest civilian series from one institution, the peripheral arteries most commonly shunted were the superficial femoral and popliteal.6 Over 50% of the shunts inserted into these vessels were either 14 or 12 Fr Argyle.
When dealing with pediatric arterial injuries, a 5 or 8 Fr feeding tube can be used. The peripheral veins most commonly shunted in the same review were the popliteal and femoral, and over 55% of the shunts inserted into these vessels were either 14 or 12 Fr Argyle. For larger veins such as the common femoral, external iliac, axillary, or subclavian, an Argyle thoracostomy tube can be used.
The length of the shunt to be inserted should be 4 cm longer than the gap between the two ends of the vessel.5 Also, a 2-0 silk tie should be placed around the midpoint of the shunt for orientation during and after insertion. The shunt is clamped at its midpoint with a hemostat and placed 1.5 cm into the proximal open end of the transected artery (or the end nearest the foot or hand of the transected vein) and fixated in place with a 2-0 silk tie. The hemostat is removed to verify the flow through the shunt and then replaced. After insertion of the distal end of the shunt 1.5 cm and fixation with a 2-0 silk tie, the hemostat is removed. The flow through an arterial shunt is verified by palpable or Doppler-audible pulsations beyond the shunt. Dilatation of the vein beyond the shunt or Doppler-audible continuous flow confirms patency of the shunt.
There are no convincing data that systemic or locally injected anticoagulation lowers the 5% to 10% postoperative rate of thrombosis of intra-arterial shunts.7 8 In addition, anticoagulation would be contraindicated in many of the patients with multiple injuries and/or ‘damage control’ patients in whom temporary intravascular shunts are inserted. The cumulative experience with shunts during the past 25 years suggests that early postoperative occlusion is most frequently due to one of the following: small shunt size (failure to dilate end of artery in spasm before insertion); or loss of venous outflow from proximal ligation or venous thrombosis related to the original injury or a narrowed repair, particularly in the lower extremity. Thrombosis of a postoperative arterial shunt is often predictive of the need for later amputation of an injured extremity.
Many shunts in patients with Gustilo IIIC fractures are removed at a first operation after orthopedic fixation allows for an easier vascular reconstruction.9 Patients with a ‘damage control’ indication, however, most commonly leave the operating room with the shunt in place. In the aforementioned large civilian review from Grady Memorial Hospital, Atlanta, Georgia, in 2008, the average ‘dwell’ time for a shunt was 23.5±15.7 hours (2–71).6 A more recent civilian multicenter review of 213 shunts in 201 patients from seven level I trauma centers over 9 years (2005–2013) listed the following dwell times: less than 6 hours—61.4% of all shunts; 24 hours—86.5%; and 48 hours—95.9%.10 The longest ‘dwell’ time for an arterial shunt in the American literature (10 days) is the patient described in this report.11
In all patients with significant injuries to a vessel managed with a shunt, bone, and soft tissue in an extremity, an extra-anatomic bypass should be considered at the time of removal of the shunt and vascular reconstruction. This approach decreases the risk of a saphenous vein graft or suture line (vessel-plastic graft) blowout secondary to later infection at the site of injury.