NOTE: See Appendix A, Appendix B and Appendix C for management based on anatomic location and Appendix F for basic equipment list

Most deploying non-vascular or non-cardiothoracic surgeons will have limited recent experience in vascular surgery. Prior to deployment, all military surgeons should take the ASSET+ course (DoD developed course currently part of the Emergency War Surgery Course). ASSET+ training was developed by military surgeons for military surgeons to given them iterative training on vascular exposures. Training for surgeons should emphasize the basic principles of vascular trauma management, including adequate exposure, proximal and distal control, vessel debridement to viable tissue, the creation of a tension-free anastomosis, repair or shunt, and adequate coverage with viable tissue. The most challenging aspect in the management of a wartime vascular injury is generally related to vascular exposure. As most of these injuries involve previously normal blood vessels, vessel suturing, and shunt placement are usually a relatively straightforward technical exercise. However, in the face of tissue destruction, hematoma, distorted anatomic landmarks, and the potential absence of a palpable pulse, the identification and adequate exposure of a wartime vascular injury can be a challenge for even an experienced surgeon. While the deploying surgeon will find additional detail regarding techniques and “pearls” in the appendices extremely valuable for pre-deployment review and as a reference during deployment, surgeons should also maximize opportunities to review anatomic exposures in cadaveric, simulation, and video settings prior to deployment. Furthermore, an atlas that covers vascular surgery and exposures should be at the immediate ready for every surgeon on a combat deployment.

LIGATION OF VESSELS

Pearls

- Acceptable damage control maneuver especially for small, more distal arteries and veins.
- Temporary vascular shunting to restore perfusion should be considered before ligation.
- Continuous wave Doppler should be checked before ligation to judge collateral perfusion/viability.
- Ligation of vascular injuries was the mainstay of treatment for centuries and should not be overlooked as a damage control option, especially at Role 2 facilities where operations are best abbreviated (≤ 1 hr). This technique is especially useful in small distal vessels (tibial, forearm and arm below the take-off of the profunda brachial artery) when patients are in extremis. Use of temporary vascular shunts or even repair should be considered before ligation; however, if not available or feasible, ligation should be completed. Continuous wave Doppler may also be useful in assessing perfusion to the extremity distal to the vessel in question. If there is loss of an arterial bypass during the operation or shortly thereafter with associated venous ligation, consideration should be made for venous reconstruction as the arterial bypass may be lost due to reduced extremity outflow.

THROMBECTOMY

Pearls

Fogarty catheters are a key tool in the armamentarium of vascular injury management. Used primarily to remove thrombus, they can also be used to arrest bleeding from within the lumen of the vessel. The most common size used in extremity vascular injury is 2 and 3 Fr. At least one pass of a Fogarty should precede extremity vascular injury repair to assure removal of the traumatic thrombus burden before restoring inflow and outflow. The key tenet is not to cause native vessel damage. To lessen the risk of damage, avoid advancing the catheter too distal in the smaller vessels of the leg and arm and avoid over aggressive, static balloon inflation (i.e. angioplasty or “intimectomy”).

- Sized at 2-7 Fr; Commonly use 2 or 3 Fr catheters. Maximum balloon diameter of the 2 and 3 Fr catheters is 4 and 5 mm.
- Inflate with saline using 1cc tuberculin syringe (max inflation listed on the Fogarty hub) while withdrawing from vessel.
- Goal is clot, not intima, removal so don’t over-inflate or “drag” too much.
- A valuable tool in assessing the distance of the catheter placement and avoiding distal intimal injury is to measure externally on the skin the distance the catheter should pass.
- May be used to control bleeding from within the vessel lumen. Requires a 3-way stop cock to maintain inflation once the bleeding has been stopped.

TEMPORARY VASCULAR SHUNTS

Pearls

- Inline shunts rest in the vessel (“in-situ”) while long external shunts are designed to loop.
- In-line Argyle shunts come in a cylinder container with 8, 10, 12 and 14 Fr sizes.
- In-line Javid shunts are longer and individually packaged with a ribbed edge to help keep secure.
- Sundt shunts are designed with short (15cm; inline) and long (30cm; external) profiles with a ribbed edge to help keep secure.
- Equal success has been had with Argyle, Javid and Sundt without systemic anticoagulation.
- Proximal and Distal embolectomy should be performed prior to shunt placement.
- When cutting the shunt to size, there should be at least 4cm longer than the gap between the injured ends of the vessel. For example, if there is a 3cm gap, the shunt should be approximately 7cm long with 2cm of the shunt in both the proximal and distal injured vessel. (Figure 1). This is to allow 2cm of the shunt to be in the proximal and distal ends of the artery.
- Do not kink the shunt, as this will create turbulent flow and increase the risk of shunt thrombosis. (Figure 2)
- When placing the shunt, be careful not to injure the intima (particularly if the shunt was cut to size) as this can result in early shunt failure and necessitate a more complex definitive repair/reconstruction.
- Secured with silk ligatures no more than 1cm from each damaged end of the vessel; edges will be debrided to health tissue beyond the ligature prior to definitive repair. (Figure 1)
- If not secured well, shunts will have a tendency to migrate distally and even become dislodged. To prevent this from occurring:
  - All ‘tails’ are used (6 in total).
  - Vessel to vessel - not tight but to stabilize the two ends of the vessel to prevent further retraction.
  - Shunt to vessel on the proximal end.
  - Shunt to vessel distally.
  - Do not leave these silk tail long or there is a risk of an en-route care provide ‘pulling up on them’ should there be a concern for bleeding. Cut all the tails and temporarily close the wound.
  - Ensure there is a way for en-route care providers to attain proximal control if there is massive bleeding (from shunt dislodgement) during transport. This can be done with a proximal (pre-positioned) tourniquet or with vessel loops that have been secured appropriately.
- Patent for up to 6 hours; reports of longer duration exist.
- Consider shunting of concomitant vein injuries if possible.
- Shunts should be removed with formal repair in-theater prior to MEDEVAC to Role 4.
- Temporary vascular shunts are effective and should be considered in the management of nearly all extremity vascular injury patterns including proximal venous injuries. Their main advantage is provision of early restoration of flow and mitigation of the damaging effects of arterial ischemia and venous hypertension. As an abbreviated procedure compared to formal vascular repair, shunting extends the window of opportunity for limb salvage in some patterns of vascular injury. Although the patency at 3-4 hours is higher in larger, more proximal vessels (axillary/brachial and femoral/popliteal), shunts have been used effectively in smaller (distal brachial/forearm and tibial) vessels. Outcomes of extremity vascular injury managed with temporary shunts have been recorded demonstrating no adverse effect of this technique and a limb salvage advantage in the most severely injured limbs (MESS ≥ 8). 3,4,8,20