Vascular Reconstruction and Limb Loss in Military Tibial Artery Injuries

BACKGROUND

Selective operative management of injuries to the tibial arteries is controversial, with the necessity of revascularization in the face of multiple tibial arteries debated. Tibial artery injuries are frequently encountered in military trauma, but revascularization practices and outcomes are poorly defined. We aimed to investigate associations between the number of injured vessels and reconstruction and limb loss rates in military casualties with tibial arterial trauma.

METHODS

A US military database of lower extremity vascular injuries from Iraq and Afghanistan (2004-2012) was queried for limbs sustaining at least 1 tibial artery injury. Injury, intervention characteristics, and limb outcomes were analyzed by the number of tibial arteries injured (1, T1; 2, T2; 3, T3).

RESULTS

Two hundred twenty one limbs were included (194 T1, 22 T2, 5 T3). The proportions with concomitant venous, orthopedic, nerve, or proximal arterial injuries were similar between groups. Arterial reconstruction (versus ligation) was performed in 29% of T1, 63% of T2, and universally in T3 limbs (P < 0.001). Arterial reconstruction was via vein graft (versus localized repair) in 62% of T1, 54% of T2, and 80% of T3 (P = 0.59). T3 received greater blood transfusion volume (P = 0.02), and fasciotomy was used universally (versus 34% T1 and 14% T2, P = 0.05). Amputation rates were 23% for T1, 26% for T2, and 60% for T3 (P = 0.16), and amputation was not significantly predicted by arterial ligation in T1 (P = 0.08) or T2 (P = 0.34) limbs. Limb infection was more common in T3 (80%) than in T1 (25%) or T2 (32%, P = 0.02), but other limb complication rates were similar.

CONCLUSIONS

In this series of military lower extremity injuries, an increasing number of tibial arteries injured was associated with the increasing use of arterial reconstruction. Limbs with all 3 tibial arteries injured had high rates of complex vascular reconstruction and eventual amputation. Limb loss was not predicted by arterial ligation in 1-vessel and 2-vessel injuries, suggesting that selective reconstruction in these cases is advisable.

American Association for the Surgery of Trauma-World Society of Emergency Surgery guidelines on diagnosis and management of peripheral vascular injuries

The peripheral arteries and veins of the extremities are among the most commonly injured vessels in both civilian and military vascular trauma. Blunt causes are more frequent than penetrating except during military conflicts and in certain geographic areas. Physical examination and simple bedside investigations of pulse pressures are key in early identification of these injuries. In stable patients with equivocal physical examinations, computed tomography angiograms have become the mainstay of screening and diagnosis. Immediate open surgical repair remains the first-line therapy in most patients. However, advances in endovascular therapies and more widespread availability of this technology have resulted in an increase in the range of injuries and frequency of utilization of minimally invasive treatments for vascular injuries in stable patients. Prevention of and early detection and treatment of compartment syndrome remain essential in the recovery of patients with significant peripheral vascular injuries. The decision to perform amputation in patients with mangled extremities remains difficult with few clear indicators. The American Association for the Surgery of Trauma in conjunction with the World Society of Emergency Surgery seeks to summarize the literature to date and provide guidelines on the presentation, diagnosis, and treatment of peripheral vascular injuries. LEVEL OF EVIDENCE: Review study, level IV.

Predictors and timing of amputations in military lower extremity trauma with arterial injury

INTRODUCTION

Military lower extremity arterial injuries present threats to life and limb. These injuries are common and limb salvage is a trauma system priority. Understanding the timing and predictors of amputation through the phases of casualty evacuation can help inform future limb salvage efforts. This study characterizes limbs undergoing amputation at different operationally relevant time points.

METHODS

A retrospective cohort study of casualties with lower extremity arterial injuries undergoing initial vascular limb salvage in Iraq and Afghanistan was undertaken. Amputations were grouped as having been performed early (in theater at Role 2 or 3) or late (after evacuation to Role 4 or 5). Further distinction was made between late and delayed (after discharge from initial hospitalization) amputations.

RESULTS

Four hundred fifty-five casualties met inclusion criteria with 103 amputations (23%). Twenty-one (20%) were performed in theater and 82 (80%) were performed following overseas evacuation. Twenty-one (26% of late amputations) were delayed, a median of 359 days from injury (interquartile range, 176-582). Most amputations were performed in the first 4 days following injury. Amputation incidence was highest in popliteal injuries (28%). Overall, amputation was predicted by higher incidence of blast mechanism and fracture and greater limb and casualty injury severity. Early amputations had higher limb injury severity than late amputations. Delayed amputations had greater incidence of motor and sensory loss and contracture than early amputations.

CONCLUSION

Casualty and limb injury severity predict predictors and timing of amputation in military lower extremity arterial injury. Amputation following overseas evacuation was more common than in-theater amputation, and functional loss is associated with delayed amputation. Future limb salvage efforts should focus on postevacuation and rehabilitative care.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

The Impact of Geniculate Artery Collateral Circulation on Lower Limb Salvage Rates in Injured Patients

BACKGROUND

This study aimed to determine the association between geniculate artery flow on admission computed tomography (CT) angiography and limb salvage outcomes in patients with lower extremity arterial injury.

METHODS

All injured patients at a level I trauma center with CT angiogram (CTA) confirmed limited or no flow to the tibial vessels were included. Demographics, injury severity score (ISS), mechanism of injury, physiological parameters, the presence of geniculate artery collateral circulation (superior medial, superior lateral, medial, inferior medial, inferior lateral), and 30-day limb salvage outcome were recorded. Statistical analysis was completed using descriptive statistics and the chi-squared tests.

RESULTS

From 2009 to 2012, a total of 84 patients with lower extremity arterial injury underwent diagnostic evaluation with CTA on admission that confirmed limited or no flow to the tibial vessels. A total of 10 patients (12%) underwent amputation. Primary amputation was performed in 3 (4%) patients, and secondary amputation was performed in 7 (8%) patients. There was no difference in age, gender, ISS, extremity abbreviated injury score, mechanism of injury, admission systolic blood pressure, heart rate, respiratory rate, transfusion volume, or type of vascular interventions between patients who had successful limb salvage and those who received an amputation. The number of patent geniculate arterial vessels was inversely associated with amputation with 3.3 patent geniculate arteries in the limb salvage group compared to 2.1 in the amputation group (P < 0.05). The 2 geniculate artery vessels that were significantly associated with limb salvage were the superior lateral geniculate and the inferior medial geniculate arteries (P < 0.05).

CONCLUSIONS

Geniculate collateral circulation may have an important role in limb salvage after lower extremity vascular injury. The geniculate arteries that are associated with the highest rates of limb salvage appear to be the superior lateral geniculate and the inferior medical geniculate artery.