Key Words:
vascular trauma , vascular surgery , endovascular , hemorrhage control , shunt
Epidemiologic Considerations
Vascular trauma in Israel includes the usual myriad of causes for vascular trauma as in other western societies. These include blunt and penetrating mechanisms, road traffic accidents, long bone fractures, and falls. Of note, more cases of iatrogenic vascular trauma are recently being encountered. Paradoxically, some of these are related to an increased use of “minimally-invasive” and laparoscopic techniques and the liberal use of angiography. On the other hand, vascular trauma caused by criminal acts is less frequent in Israel than in some western societies; but this type of trauma also seems to be increasing recently. Above all of the regular civilian causes of vascular trauma in Israel is the country’s great experience with combat-related injury.
Israel is a small-sized western country of 7 million citizens with a special geopolitical status ( Fig. 31-1 ). It is surrounded by hostile neighbors and constantly threatened by close and remote enemies. Israel is actively engaged in daily defense acts and periodic wars of small or large magnitude an average of every 6 to 10 years. In the short period of time since the beginning of the 21st century, Israel has suffered the wave of terrorism of the Second Intifada of 2000-2005, the 2006 Lebanon War, and the Cast Lead event of 2008, as well as multiple terrorist attacks in between. In total, these clashes have caused about 1500 deaths and 8000 casualties, mostly civilian. The rate of vascular trauma among these casualties is relatively high. Unfortunately, in the absence of peace agreements and in the wake of major political changes now taking place in the Middle East, more such events are expected.
During these types of hostilities, even civilian medical centers (themselves treating casualties) have been targeted both by suicide bombers and by short- and medium-range rockets. In fact, all major Israeli hospitals are within the range of missiles and rockets that are readily available to the surrounding conflict countries and terrorist groups. Also, public venues, buses, restaurants, and hotels are purposely targeted by attackers to maximize casualties. Weapons are also designed to increase destruction by using rockets containing high explosives covered by thousands of pellets and other types of fragments ( Fig. 31-2 ). These rockets are mostly inaccurate but may prove highly lethal if they happen to fall amid a crowd. In one case in a railroad station, 8 civilians bled to death; and, in another, 12 soldiers died mainly from bleeding vascular injuries. Altogether Northern Israel was attacked by more than 4000 rockets from Lebanon in the 2006 war, and Southern Israel was attacked by 2000 rockets from Gaza.
The threats to the security of the public are now so severe, and the potential for use of weapons of mass destruction so high, that Israel is preparing for more casualties in the future including building shelters for mass casualties and building underground fortified hospitals. A 1000-bed underground emergency hospital has been built in the city of Tel Aviv, and a 2000 bed sheltered hospital is being completed in Rambam Health Care Center in the city of Haifa ( Fig. 31-3 ). More such facilities will be built in the future and integrated military and civilian medical drills are conducted periodically to increase preparedness.
Another consideration for the field of vascular trauma is that the distances from the peripheral regions and front lines to major hospitals are relatively short, and evacuations by designated helicopters are preferred ( Fig. 31-4 ). For example, Rambam Health Care Center is less than 50 km from the Lebanese border and less than 80 km from the Syrian border ( Fig. 31-1 ). These facts result in relatively brief evacuation times and contribute to decreasing mortality and limb loss from vascular trauma.
Incidence of Vascular Trauma
Vascular injuries are relatively uncommon but vary widely in the civilian trauma experience, ranging from 0.6% of all patients to 30% in specific injuries such as posterior knee dislocation. In battlefield trauma, the reported incidence of vascular injuries has been historically low with a range of only 0.2% to 4% of all injuries. This low incidence was probably due, in part, to excessive mortality of vascular patients during prolonged evacuation time and to limited treatment options. In more-recent reports from the Iraq War this incidence increased to 6.8% due to improved immediate resuscitation and quick evacuation from the battleground. Even more so, in our recent experience of the 2006 Lebanon War, the rate of vascular trauma increased to 7.6% of all casualties and 10.8% in the subgroup of soldiers only. Vascular injuries are mostly caused by penetrating trauma due to penetrating fragments, high-velocity bullets, and pellets ( Fig. 31-2 ). Less frequently, blunt trauma is the cause of vascular trauma. In modern armies better torso protection of soldiers by advanced ceramic armored vests is afforded. The use of torso body armor may have increased the frequency of survivable extremity vascular injury and may have led to recognition of what are referred to as junctional vascular injuries (i.e., those between the torso and the extremities). Almost half (46%) of all combat-related vascular injuries affect the lower extremities, and almost a quarter affect the upper limbs. All grades of vascular injuries are now encountered, better diagnosed, and better treated. These range from small intimal flaps that do not require immediate interventions, to bleeding sources that may be stopped by catheter-based embolization, to complete transection of large vessels that are life threatening.
Evacuation Methods of Vascular Injuries
Rapid evacuation from the arena of injury to the nearest surgical facility is of utmost importance in vascular trauma. The time factor is important both in reducing continued bleeding and in reducing tissue ischemic time of the injured limb when tourniquets are applied. Emergency evacuation should be ordered otherwise mortality may ensue. Evacuation by helicopter is the most rapid method when the vascular facility is remote. However, ground vehicles may prove to be faster when the arena is close.
Evacuation Methods of Vascular Injuries
Rapid evacuation from the arena of injury to the nearest surgical facility is of utmost importance in vascular trauma. The time factor is important both in reducing continued bleeding and in reducing tissue ischemic time of the injured limb when tourniquets are applied. Emergency evacuation should be ordered otherwise mortality may ensue. Evacuation by helicopter is the most rapid method when the vascular facility is remote. However, ground vehicles may prove to be faster when the arena is close.
Israeli Vascular System of Care
The organization of the area of vascular trauma in Israel should be put in the complex context as described earlier. Specialized vascular units and trained vascular surgeons are present in almost all public hospitals in Israel, and all are ready to provide 24-7 immediate vascular care as part of their daily routine. However, at times of major armed conflicts most evacuations are designated to go to Level I trauma and vascular centers. There is one such center in the north of Israel, three in the populated center of the country, one in Jerusalem, and one in the south ( Fig. 31-1 ). During such events military medical officers, using mainly airborne evacuation, take responsibility for organizing and setting priorities of evacuation ( Fig. 31-4 ).
There is close contact and good collaboration between trauma and vascular specialists within these Level I trauma centers to allow the best approach and outcome for those with vascular injury. This collaboration is of utmost importance in complex cases of shock, multiple system injuries, and mangled extremities. Vascular repairs are always done by a qualified vascular surgeon ( Fig. 31-5 ).
Considerations for Diagnosis
Physical examination is the mainstay for the diagnosis of vascular injuries. Classical “hard signs” include active hemorrhage; large, expanding, or pulsatile hematoma; palpable thrill or audible bruit; and distal ischemia (with the well-known 6 Ps: pain, paralysis, paresthesias, pallor, pulselessness, and poikilothermy). Precise identification of vascular trauma is of utmost importance for the success of treatment. However, in complex modern vascular injuries with multiple penetrating wounds, the exact extent, severity, and location of the injury are not always straightforward. High quality vascular imaging helps to identify such injuries ( Fig. 31-6 ). In other cases, imaging may exclude significant injuries, especially in patients with hypovolemic shock, large hematomas, and large bone fractures. In these cases an unnecessary exploration may be avoided. Vascular duplex scanning in trauma is seldom used in Israel since this modality is observer dependent, has low specificity, and is time consuming.
The routine use of old gold-standard angiography is no longer indicated because of its time consumption, which may spans hours; its risks; and its inherent inaccuracies, including a 15% false negative rate. Instead, multislice CT angiography (CTA) with rapid reconstruction is our preferred method of imaging in all cases of vascular trauma. CTA is rapid, accurate, and provides additional information such as size of hematoma, presence of unexpected periarterial hematoma, bone fragment compression, additional injuries, proximity of penetrating fragments, and additional detail ( Fig. 31-7 ). All vascular centers in Israel are well equipped with modern multislice CT scanners. The use of angiography in vascular trauma is reserved for only therapeutic interventions like embolization, use of covered stents when indicated, and closure of traumatic arteriovenous fistulas.
Treatment Strategies
In vascular trauma the goal of treatment is twofold: first, to stop continued bleeding to prevent possible mortality; then, second, to restore flow to and to revascularize ischemic tissues. Speed is an important factor since irreversible damage may result within 6 hours or less in the setting of shock.
Hemorrhage Control
Patients with limb vascular trauma are frequently saved from exsanguination by liberal use of rubber tourniquets that are available to all paramedics and to almost every soldier in the battlefield. Improvised tourniquets are seldom needed ( Fig. 31-8 ). Local prolonged hand pressure to stop bleeding is used only temporarily until a tourniquet can be applied. Specialized compression devices are under investigation but are not yet in practice. The liberal use of tourniquets and prompt removal on arrival at the hospital seem to save lives without the serious side effects of secondary ischemia or nerve injury.
Extremity vascular injuries were associated with an approximate 9% to 10% mortality rate due to exsanguination. Tourniquets are the basic equipment of every medical team in Israel to control both civilian and battlefield hemorrhage. Proper use of tourniquets may indeed save lives. However, unnecessary or prolonged use may result in limb ischemia and paralysis, which may lead to amputation. Moreover, improper use may not stop the bleeding. Tourniquets were utilized in 3% to 8% of extremity injuries in Iraq. In the Israeli Defense Force every soldier has access to a tourniquet that can be used when necessary, even without the presence of a medical team. In our 2006 Lebanon War experience, tourniquets were liberally used in 39% of extremity vascular injuries and were removed only in the operating room. Tourniquets were beneficial in 11 patients and overused (abused) in 2 patients without adverse effects. In a recent publication, 8 tourniquets were used at Kandahar Airfield Base: 5 saved lives, 1 was misused, and 1 overused. Prehospital tourniquet use in Operation Iraqi Freedom was associated with improved hemorrhage control without adverse outcomes related to its use. These findings support liberal use of tourniquets and refute the policy of their utilization as a last-resort option.
Triage in the Emergency Room
Vascular injuries take priority in treatment paradigms since shortening the time of bleeding and ischemia are of paramount importance in saving lives and limbs of the injured. When a vascular injury is identified, the patient is rushed to the operating room without delay. When such injuries are suspected by physical examination but are not certain, then vascular imaging is required. A simple hand-held Doppler apparatus is very helpful in identifying arterial flow in the dorsalis pedis or the tibialis posterior arteries, especially in patients with vasospasm from hypothermia or reduced blood pressure. Sophisticated duplex ultrasound machines have yet to prove efficacy in the treatment algorithm of the suspected vascular injury.
Priority in the Operating Room
The first priority in the operating room is controlling blood loss. If tourniquets are still applied, they should be released as soon as possible under controlled conditions. If bleeding resumes, direct pressure is applied on the point of bleeding; and proximal control of the artery is gained. Distal control is also required to reduce bleeding. Then the injured segment of the vessel is approached and repair is started by standard vascular methods. If the patient is successfully stabilized with no more bleeding, we use intravenous heparin to avoid secondary thrombosis of the injured blood vessels. Only after bleeding is stopped and revascularization is secured are other necessary fixations and repairs undertaken. Intensive care unit is recommended for 24 hours following surgery due to hypovolemic shock, reperfusion injury, hypothermia, and bleeding diathesis.
Methods of Vascular Repair Employed
Simple repair of injured blood vessels is preferred ( Fig. 31-9 ). Lateral suture and end-to-end anastomosis when possible are rapid and effective with few complications. Venous interpositions and bypasses are used when a longer arterial segment is injured. Synthetic bypasses should be avoided if possible. All vascular repairs should be well covered by viable clean tissue to prevent late infection and bleeding. In our recent experience, interposition venous grafts were used in 38% of cases, end-to-end anastomosis in 23%, and lateral repair or patch in 16%; whereas primary ligation was reserved for small arteries and for veins (8%). Extraanatomic bypasses are rarely required ( Fig. 31-10 ).
