Due to low incidence and specific anatomic and physiological characteristics, vascular injuries in children are a great challenge in terms of diagnostics, operative treatment and perioperative management. Furthermore, the question of limb salvage in children with vascular injuries confronts surgeons with major problems. The aim of the present study was to investigate the epidemiology, diagnostic and therapeutic options and complications in traumatic extremity paediatric vascular injuries and to evaluate the prognostic value of the Mangled Extremity Severity Score (MESS). The major findings were that 1) traumatic extremity paediatric vascular injuries are very rare even at a Level I trauma center, 2) that the most common situations of traumatic vascular lesions in childhood were penetrating injuries and fractures of the extremities either as isolated injuries or in multiply injured patients, and 3) that the MESS could serve as a basis for decision making for limb salvage or amputation in paediatric patients.
We are aware that our study has some limitations. One of the most important limitations is the study design as a retrospective review of a consecutive case series over a long time period. Due to the low incidence of paediatric vascular injuries [1–6], a long observation span is always needed in order to create an adequate study population. In the present study only traumatic arterial lesions were enrolled. Therefore venous and iatrogenic vascular injuries were excluded. Because an age ≤ 14 years is more adequate for a paediatric population children older than 14 years were also excluded. Although an additional long observation period is caused, these exclusion criteria make the present study very unique. Most of the current studies investigate mixed patient populations of children and young adults aged up to 18 years with iatrogenic and traumatic injuries . In contrast, Lazarides et al. observed vascular injuries of the extremities over a 10-years study period in children aged 13 years or younger . But again, iatrogenic as well as traumatic arterial injuries were included in this study . Bearing in mind that iatrogenic lesions make up one third of vascular injuries [7–10] our study represents a large series of 44 traumatic arterial injuries.
In accordance to the current literature [19–21], the most common situations of paediatric vascular lesions in the present study were penetrating injuries (31.8%) and either isolated fractures of the extremities or in polytraumatized patients. With 34.8% penetrating lesions Lazarides et al. reported comparable figures . Due to a high rate of gun shot wounds (70.8%) penetrating vascular injuries were observed much more often (91.7%) in a study of De Virgilio et al. at a major U.S. trauma center . In our study there were no gun shot injuries. The vast majority was due to stab and cut wounds. Humeral supracondylar fractures with vascular lesions were rare in our study population (13.6%). The incidence of neurovascular complications in supracondylar fractures is up to 24% [22, 23]. Due to good vascular collateralisation at the upper extremity [24, 25], an obstruction of the brachial artery sometimes does not become clinically apparent. In a series of 143 supracondylar fractures Shaw et al. reported an ischemia at presentation in 12% . A remaining ischemia after fracture reduction was observed in three cases (2.1%). In general, persistent ischemia after reduction of supracondylar fractures is rare [27–29]. Accordingly, in the present study an adequate vascular perfusion was achieved after fracture reduction in 66.7% of supracondylar fractures. Good vascular collateralisation and commonly achieved vascular reperfusion after fracture reduction maybe explain why vascular injuries are often not registered in supracondylar fractures.
In accordance to De Virgilio et al., who reported an affection of the lower extremities in 64.6% and the upper extremity in 35.4% , in the present study the lower extremity was affected most frequently followed by the upper extremity. Lazarides et al. observed an almost equal distribution between upper (56.5%) and lower extremity (43.5%) . In contrast to the current literature [10, 30], in our study population the brachial artery (22.7%) was affected less frequently than the femoral artery (25%) caused by the lower incidence of supracondylar fractures.
In the present study, most patients (63.6%) received no specific vascular diagnostics, especially patients with supracondylar fractures, penetrating injuries and isolated blunt extremity trauma. In contrast, vascular diagnostics were performed in 72.7% of multiple trauma patients. Because of subsequent potential deterioration in multiple trauma patients, the preoperative examination of vascular lesions might be of special interest in order to avoid long surgical procedures with intraoperative evaluation of vascular injuries. In penetrating injuries and isolated blunt extremity trauma the danger of subsequent deterioration due to the second hit of the operative procedure is negligible. Furthermore, routine surgical revision of the soft tissues is required and the intraoperative examination of vascular lesions is probably easily performed. This might explain the higher rate of vascular diagnostics in multiple trauma patients. The fact that no vascular diagnostics were performed in supracondylar fractures could be explained by the frequent clinical inapparence at the time of admission as described above [24–26].
Compared to current studies, which report limb salvage rates of 87-100% in paediatric vascular injuries [1, 10], a limb salvage was achieved less frequently (81.8%) in the present study. Due to the exclusion of venous and iatrogenic lesions, the severity of vascular injuries might be higher in our study population explaining the lower limb salvage rate. This might be also the explanation for the higher rate of postoperative complications with vascular occlusion (13.6%) and secondary peripheral ulcers (4.5%) compared to a study of Lazarides et al. who observed none of these complications after surgical repair or medical treatment of 23 children with arterial trauma of the extremities . In a series of 550 adult patients with traumatic lower limb arterial injuries Hafez et al. reported a failure rate of 8% after surgical vascular repair indicating the more sophisticated surgical procedures in children .
The prognostic value of the MESS in children remains questionable as most of the available studies dealt with adults. A 100% predictable value of a MESS score greater than or equal to 7 for amputation is described in adults [11, 12]. Bosse et al. reported in a series of 556 lower extremity trauma a definitive limb salvage of 34.6% in adults with MESS ≥ 7 and 82.1% in patients with MESS < 7 . Few data on paediatric injuries are available. Besides some reviews of paediatric open fractures [13–16], there is one retrospective investigation focussing on the relevance of the MESS in 36 children with grade IIIB and IIIC open lower extremity fractures . Fagelman et al. reported a limb salvage of 28.6% in patients with a MESS ≥ 7 and 89.7% in patients with a MESS < 7, respectively .
In the present study, we found comparable limb salvage rates of the lower extremity (n = 27). Definitive limb salvage was achieved in 33.3%, when the MESS was greater than or equal to 7, whereas the affected extremity could be salvaged in 100% in children with a MESS < 7. Unlike adults, in whom initial amputation rates of 43-46% are reported [12, 32], in our study a primary amputation in children with a MESS ≥ 7 was performed less frequently (25%). In summary, the MESS could serve as a basis for prediction of limb salvage in children. But it has to be pointed out, that according to our results in one third of the children with a MESS ≥ 7 a limb salvage could be achieved. Therefore, the decision for limb salvage or primary amputation has to be made individually. Furthermore, the present study is limited by the number of patients and its retrospective design. Especially, the retrospective application of the MESS to the treatment of paediatric vascular injuries before the development of the score in 1990 is a weakness. Moreover, in the MESS age is not really pertinent as it remains a constant. Additionally, many of the included children were managed before modern diagnostic and therapeutic methods were developed. Advances in imaging and operative treatment of vascular and soft tissue injuries have undoubtedly influenced limb outcomes after trauma. In a prospective study with an increased MESS threshold for primary amputation (MESS ≥ 10), Lin et al. reported a successful limb salvage in 75% . In general, further studies analysing a larger patient population by prospective - preferably randomized controlled - study design are required in order to validate the results of the present study.