Aortic aneurysm screening using duplex ultrasound: Choosing wisely who to examine.

The noninvasive vascular laboratory plays a critical role in screening patients at risk for development of abdominal aortic aneurysm (AAA). One-time duplex ultrasound screening reduces aneurysm-related mortality due to rupture and is cost-effective. Population screening based on AAA risk factors is recommended, as it allows for proactive, elective repair of aneurysms at risk for rupture, and surveillance of smaller aneurysms for enlargement. Utilization of societal screening guidelines, such as those published by the Society for Vascular Surgery, can be employed by vascular laboratories to justify individual patient screening, aid primary care physicians to refer patients for testing, and encourage integrated medical health care systems to build prompts in patient electronic health records to ensure compliance with a AAA screening program. Risk factors for developing AAA, that is, age older than 65 years, male sex, family history, and a smoking history of >100 cigarettes, should be used to recommend patient screening, including for women and other elderly (older than 75 years) patients who fall outside of professional societal guidelines.

Analysis of Limb Outcomes by Management of Concomitant Vein Injury in Military Popliteal Artery Trauma.

BACKGROUND: Despite aggressive limb salvage attempts, military popliteal artery injuries are associated with high amputation rates. Combined arterial and venous injuries present a management dilemma for military surgeons in austere settings, and the impact of vein injury management strategy on limb outcomes is not clear. METHODS: Military casualties sustaining combined ipsilateral popliteal artery and vein injuries from 2003 to 2016 were identified from a military vascular injury database. Limbs were grouped based on whether venous ligation or repair was initially performed. The primary outcome was secondary amputation; the secondary outcomes included limb and vascular/graft complications. RESULTS: Fifty-six limbs were included; of which, 27 (48%) were managed with vein ligation and 29 (52%) with repair. Veins were repaired primarily in 13 (45%) cases with the remainder being treated with interposition grafts. Median injury severity score was higher in the ligation group (19 vs 15, P = 0.09), but vascular and concomitant limb injury characteristics were similar. Amputation rates did not differ by vein treatment (45% repair vs. 41% ligation, P = 0.76), and this held with injuries above and below the knee considered independently. Most (71%) amputations were performed <30 days from injury. Amputation was indicated more frequently for vascular repair failure in the ligated group (55% vs 15%, P = 0.04). Four graft infections were all in the repair group (P = 0.07 vs ligation). Arterial graft complications were more frequent with vein repair (45%) than ligation (30%), but this did not reach significance (P = 0.24). Only one deep vein thrombosis was diagnosed in each group (P = 0.96). CONCLUSIONS: Type of management of concomitant popliteal vein injury was not associated with early or late amputation in this series of military popliteal artery injuries. Vein injury management may have had implications for the development of arterial graft and limb complications, however. Surgical decision-making regarding popliteal vein treatment should balance short-term contingencies with long-term limb salvage issues.

Successful Use of Nellix and Endovascular Aortic Sealing Technology for Treatment of Aortic Rupture in a Porcine Model.

BACKGROUND: Endovascular aortic sealing (EVAS) represents a recent transformation in approach for treatment of aortic aneurysms. Initial reporting has shown that EVAS using the Nellix device is safe with similar complication rates to standard endovascular aortic repair (EVAR). What remains unknown is how EVAS technology will behave in the ruptured setting. The purpose of this report is to discuss how EVAS system and endobag technology behave when deployed in a porcine model of aortic rupture. METHODS: A controlled left retroperitoneal rupture was created in 20 large swine. Following rupture, an EVAS system was deployed across the rupture site to seal the area. The primary end point was seal from ongoing hemorrhage. Other parameters were examined to include endobag extravasation, aortic wall pressure measurements and device behavior in a live tissue model. RESULTS: Of the EVAS systems used, 15 Nellix (Endologix, Irvine, CA) devices and 5 novel EVAS systems were used. Of the correctly deployed devices, 100% sealed the rupture (n = 19). One device was deployed above the rupture site, and seal was not achieved secondary to malpositioning. Endobag extravasation was seen with an average protrusion of 7.7 mm. No other areas of aortic injury were noted secondary to endobag trauma. Pressure recording from behind the endobag indicates loss of pulsatile flow to the aortic wall with polymer curing. CONCLUSIONS: Endovascular aortic sealing for rupture is feasible and performs well in a porcine model of aortic rupture. Polymer extravasation is seen and may be controllable by the implanter. Once the polymer has cured, pulsatile aortic wall pressure is no longer present. EVAS represents an emerging technology for treatment of aortic rupture.

Impact of femoropopliteal endovascular interventions on subsequent open bypass.

OBJECTIVE: An endovascular-first approach has been widely adopted as an alternative to surgical bypass in patients who need lower extremity revascularization for femoropopliteal disease. This study evaluated anatomic changes in the extent of bypass and outcomes of open bypass (OBP) surgery after failed endovascular treatment (EVT). METHODS: We reviewed consecutive patients treated by endovascular femoropopliteal revascularization from 2002 to 2012. Patients requiring OBP after failed EVT were analyzed. Blinded investigators reviewed preoperative and postintervention angiographies. The location of the intended distal anastomosis before the endovascular intervention was compared with the open procedure after failed EVT, and results were analyzed for amputation and patency rates. RESULTS: There were 566 patients (322 men [57%]) who underwent 836 endovascular femoropopliteal revascularizations in 665 limbs. Patients were a mean age of 72 ± 11 years. Mean follow-up was 20 months. Indication for revascularization was critical limb ischemia in 33% of patients before the index endovascular procedure. Interventions were performed for de novo lesions in 604 procedures (72%) or restenosis in 232 (28%). TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease A and B lesions were treated in 547 patients (65%). Balloon angioplasty was used in 822 interventions (98%), with primary or secondary stenting using self-expandable stents performed in 367 (44%). Thirty OBPs were required in 566 patients (5.3%) at an average of 15 months after the index EVT. OBP consisted of 6 above-knee, 14 below-knee, and 10 tibial bypasses. Vein and prosthetic conduits were used equally. Location of the distal anastomosis changed to a more distal target in 13 (5 below-knee and 8 tibial) of 30 patients (43%). Median follow-up was 36 months (range, 0.5-104 months), with a primary patency of 66% at 1 year and 46% at 3 years. Of the 30 bypasses, seven patients required reintervention with percutaneous angioplasty (n = 4) and patch angioplasty (n = 3). Five patients required redo bypass after failed endovascular salvage (lysis or angioplasty, or both), and redo bypass was not attempted in two. Eight patients (27%) progressed to major amputation, for an amputation-free survival of 79% at 1 year and 67% at 3 years. CONCLUSIONS: OBP after failed EVT was needed in a minority of patients. A change in the bypass target to a more distal site was identified in nearly half of patients. Although an endovascular-first approach to treating claudication and critical limb ischemia is safe and resulted in few progressing to OBP, poor outcomes of open interventions after EVT can be expected if EVT fails.

The natural history and outcomes for thoracic and abdominal penetrating aortic ulcers.

OBJECTIVE: The objective of this report was to define the natural history of penetrating aortic ulcers (PAUs) in the descending thoracic and abdominal aorta. METHODS: Data from consecutive patients with PAU from January 1, 1998 to December 31, 2012 were retrospectively reviewed. Computed tomography (CT) scans were analyzed for anatomic changes. End points analyzed were changes in size, development of symptoms or signs of rupture, morbidity, and mortality. RESULTS: Ninety-three patients were identified; 57 were followed up with two or more CT studies 3 months apart (group 1), and 20 had immediate repair (group 2). Sixteen had one CT scan and no intervention or follow-up and were excluded from analysis. In group 1, mean age was 75 years (29 men, 28 women), with 28 descending thoracic aorta and 29 abdominal aorta PAUs. Fifty patients were asymptomatic, whereas five had pain and two had emboli. Mean follow-up was 38 months (range, 3-108 months). Ulcer growth rate was as follows: length, 2.0 mm/y; depth, 1.2 mm/y; and aortic diameter, 2.2 mm/y. Thirteen (23%) went on to repair at a mean of 37 months after diagnosis because of size (54%; 7/13), rapid growth (31%; 4/13), and high-risk morphology (15%; 2/13). During surveillance, 11 patients died, 10 of unrelated causes, and 1 of rupture after refusing repair. All repairs in group 1 were endovascular. The 30-day surgical mortality was 0%. One patient had an access site complication requiring bypass after descending thoracic aorta PAU repair. At a mean follow-up of 32 months, all ulcers were excluded on CT; one (8%) had a type II endoleak. Group 2 included 13 men and seven women with a mean age of 70 years, with 12 descending thoracic and eight abdominal aorta PAUs. Repair indications were rupture (n = 3), symptoms (n = 10), or size (n = 7) and included one open and 19 endovascular repairs with 0% 30-day mortality. Major complications (3/20; 15%) included myocardial infarction, access site disruption, and hematoma; four of 20 patients had type II endoleaks. CONCLUSIONS: PAU growth rate and risk of rupture are low. Endovascular repair of symptomatic, ruptured, and large PAUs is safe and effective with excellent long-term results. For asymptomatic PAUs, serial CT surveillance is associated with a low rate of rupture or complications.

A retrospective cohort comparison of expanded polytetrafluorethylene to autologous vein for vascular reconstruction in modern combat casualty care.

BACKGROUND: Reconstruction of vascular injury often requires use of a conduit, either autologous vein (AV) or expanded polytetrafluorethylene (ePTFE). The most common anatomic locations for and durability of ePTFE as an adjunct to vascular repair in the combat setting are unknown. The objectives of this study were to characterize the anatomic locations of use of ePTFE during the wars in Afghanistan and Iraq and to compare its effectiveness to AV. METHODS: US service personnel undergoing vascular repair (2002-2012) were identified. Patients in whom ePTFE was used as an interposition conduit (n = 25) were matched with similar patients who received AV (n = 24) reconstruction. Injury and operative factors were assessed, and freedom from graft-related complication was quantified using Kaplan-Meier log-rank test. RESULTS: There was no difference between ePTFE and AV with regard to age, injury severity, or mangled extremity severity score. Follow-up for the ePTFE and AV groups was 71 and 62 months, respectively. In the cohort there was an apparent but not significantly greater freedom from graft-related complication for AV compared with ePTFE (65% vs. 17%; P = 0.13). In the carotid, subclavian, and axillary artery positions, ePTFE performed equal to AV with no apparent difference in freedom from graft-related complications (P = 0.90). However, in the periphery, AV demonstrated greater 8-year freedom from graft-related complication than ePTFE (77% vs. 31%, P = 0.044). CONCLUSIONS: AV is a more durable conduit than ePTFE in repair of wartime extremity vascular injury, whereas ePTFE is effective and durable in the carotid, subclavian, and axillary locations.

Pneumatic compression for embolic protection during upper extremity endovascular intervention.

Embolic protection devices are occasionally employed during endovascular interventions to prevent complications caused by embolic debris. However, these devices have imperfect efficacy, confer risk of endovascular trauma, and are expensive. We report a patient with giant cell arteritis and symptomatic axillary artery stenosis, with a perceived elevated risk of distal embolization during endovascular intervention. We describe a straightforward embolic protection technique of brachial pressure cuff inflation during endovascular intervention and aspiration of displaced thrombotic material from the static column of blood. This novel, effective, and cost-free technique could also be employed in other vascular beds during endovascular intervention.

Reflux in the below-knee great saphenous vein can be safely treated with endovenous ablation.

BACKGROUND: Intervention on the great saphenous vein (GSV) has traditionally been limited to the above-knee (AK-GSV) segment for fear of saphenous neuralgia in spite of incompetence demonstrated in the below-knee (BK-GSV) segment. Residual symptoms and need for reintervention are reported to result in nearly half the patients if the refluxing BK-GSV is ignored. Experience with endovenous ablation of the BK-GSV at the time of AK-GSV treatment is sparsely reported in the literature. The aim of this study was to evaluate the safety of endovenous ablation of the refluxing BK-GSV. METHODS: Data from consecutive patients treated with superficial venous ablation during a 48-month period from January 2010 to December 2013 were retrospectively reviewed. Demographic and procedure-related outcome and complication data were analyzed specifically for patients undergoing BK-GSV interventions. RESULTS: A total of 550 patients were treated with superficial venous ablation during the study period. Of those, 61 (79 limbs) underwent BK-GSV ablation for reflux at this site. There were 36 women and 25 men (mean age, 55 years). Median Clinical, Etiologic, Anatomic, and Pathologic (CEAP) score was 3.4; 43 limbs were treated for symptomatic varicose veins (C 1-3) and 36 for advanced venous insufficiency (C 4-6); 14 limbs (18%) were treated for recurrent symptomatic varicose veins or venous insufficiency after prior superficial venous intervention with AK-GSV ablation, sclerotherapy, or stripping. Comorbidities included obesity (54%) with mean body mass index of 30.7 (range, 19 to 52), obstructive sleep apnea (10%), pulmonary hypertension (3%), and congestive heart failure (3%). Ablation was performed in 77 limbs (99%) with the VenaCure EVLT laser vein treatment (AngioDynamics, Queensbury, NY) and in two limbs by radiofrequency ablation with ClosureFAST system (VNUS Medical Technologies, San Jose, Calif). The mean length of GSV ablated was 51.2 cm (range, 26-67 cm). Endovenous ablation was performed concomitantly on 22 accessory GSVs (28%) and 10 incompetent perforators (13%). Ambulatory stab phlebectomy of branch varicosities was performed simultaneously in 59 limbs (75%). All veins treated were evaluated with ultrasound on postprocedure day 1, and no evidence of endovenous heat-induced thrombosis was detected. Eight patients (10%) went on to have preplanned sclerotherapy treatment for small-branch varicosities. Postoperative paresthesia occurred in three patients (4%) and resolved within 4 weeks. Wound infection in three (4%) stab phlebectomy wounds resolved with oral antibiotic therapy. Follow-up surveillance ultrasound was available in 32 of 79 limbs that were >6 months from the procedure. Partial late recanalization was noted in four of 32 limbs, but no patient had recurrent symptoms requiring repeated endovenous ablation during this period. CONCLUSIONS: Endovenous ablation of the refluxing BK-GSV segment can be performed safely with minimal complications. Consideration should be given to concomitant ablation of the BK-GSV in treatment of patients with varicose veins with reflux extending to the BK segment of the GSV to improve long-term outcomes.

Biochemical markers of acute limb ischemia, rhabdomyolysis, and impact on limb salvage.

Biochemical markers of ischemia reperfusion injury have been of interest to vascular surgeons and researchers for many years. Acute limb ischemia is the quintessential clinical scenario where these markers would seem relevant. The use of biomarkers to preoperatively or perioperatively predict which patients will not tolerate limb-salvage efforts or who will have poor functional outcomes after salvage is of immense interest. Creatinine phosphokinase, myoglobin, lactate, lactate dehydrogenase, potassium, bicarbonate, and neutrophil/leukocyte ratios are a few of the studied biomarkers available. Currently, the most well-studied aspect of ischemia reperfusion injury is rhabdomyolysis leading to acute kidney injury. The last 10 years have seen significant progression and improvement in the treatment of rhabdomyolysis, from minor supportive care to use of continuous renal replacement therapy. Identification of specific biomarkers with predictive outcome characteristics in the setting of ischemia reperfusion injury will help guide therapeutic development and potentially mitigate pathophysiologic changes in acute limb ischemia, including rhabdomyolysis. These may further lead to improvements in short- and long-term surgical outcomes and limb salvage, as well as a better understanding of the timing and selection of intervention.

Interpreting comparative died of wounds rates as a quality benchmark of combat casualty care.

BACKGROUND: The died of wounds (DOW) rate is cited as a measure of combat casualty care effectiveness without the context of injury severity or insight into lethality of the battlefield. The objective of this study was to characterize injury severity and other factors related to variations in the DOW rate. METHODS: The highest monthly DOW (HDOW) and lowest monthly DOW (LDOW) rates from 2004 to 2008 were identified from analysis and casualty report databases and used to direct a search of the Joint Theater Trauma Registry. Casualties from the HDOW and LDOW were combined into cohorts, and injury data were analyzed and compared. RESULTS: The HDOW rates were 13.4%, 11.6%, and 12.8% (mean, 12.6%), and the LDOW rates were 1.3%, 2.0%, and 2.7% (mean, 2.0%) (p < 0.0001). The HDOW (n = 541) and LDOW (n = 349) groups sustained a total of 1,154 wounds. Injury Severity Score was greater in the HDOW than the LDOW group (mean [SD], 11.1 [0.53] vs. 9.4 [0.58]; p = 0.03) as was the percentage of patients with Injury Severity Score of more than 25 (HDOW, 12% vs. LDOW, 7.7%; p = 0.04). Excluding minor injuries (Abbreviated Injury Scale score of 1), there was a greater percentage of chest injuries in the HDOW compared with the LDOW group (16.5% vs. 11.2%, p = 0.03). Explosive mechanisms were more commonly the cause of injury in the HDOW group (58.7% vs. 49.7%; p = 0.007), which also had a higher percentage of Marine Corps personnel (p = 0.02). CONCLUSION: This study provides novel data demonstrating that the died of wounds rate ranges significantly throughout the course of combat. Discernible differences in injury severity, wounding patterns, and even service affiliation exist within this variation. For accuracy, the died of wounds rate should be cited only in the context of associated injury patterns, injury severity, and mechanisms of injury. Without this context, DOW should not be used as a comparative medical metric.

Methylene blue enteric mapping for intraoperative localization in obscure small bowel hemorrhage: report of a new technique and literature review: combined intraoperative methylene blue mapping and enterectomy.

BACKGROUND: Small bowel sources of obscure gastrointestinal bleeding present both a diagnostic and therapeutic challenge. Due to the normal external appearance of the vast majority of small bowel lesions that cause obscure gastrointestinal bleeding, multiple methods of intraoperative localization have been reported. When an arteriographic abnormality is found, the use of vital dye enteric mapping is one of the most effective localization techniques. CASE REPORT: We present a new technique combining superselective mesenteric angiography with methylene blue enteric mapping and small bowel resection performed during the same operative procedure. This technique was successfully applied in a patient with a jejunal arteriovenous malformation. Included is a review of methods of intraoperative localization with a focus on vital dye staining-guided enterectomy.

The ischemic threshold of the extremity.

Military efforts to limit ischemic time and reperfusion injury are being investigated with a focus on functional limb salvage as opposed to the more historic statistical salvage, since a dysfunctional limb may be a worse outcome than amputation. Translatable animal research, supported by reports from forward deployed surgeons in the field, is needed to improve care. Current studies have determined the threshold for meaningful recovery is less than 6 hours. Attempts at modeling vascular injury and ischemia reperfusion can be divided into 2 categories: chronic ischemia that mimics human age related disease and acute vascular injury that represents traumatic injury. A swine model to evaluate battlefield injuries and scenarios encountered in traumatic extremity vascular injury with a focus on functional limb salvage has been developed. Future endeavors should focus on understanding the factors that affect ischemic threshold as well as testing therapeutic and physical maneuvers to prolong this threshold.

Inferior mesenteric artery aneurysm in the setting of chronic colonic vascular ectasia.

Colonic vascular ectasia is a condition characterized by dilated submucosal veins, venules, or capillaries found commonly in patients with lower gastrointestinal hemorrhage. We present a case of colorectal ectasia associated with ischemia and an inferior mesenteric artery aneurysm. These pathologic findings may be the result of the vascular ectasia and may add to the natural history of this condition.

The impact of ischemic intervals on neuromuscular recovery in a porcine (Sus scrofa) survival model of extremity vascular injury.

BACKGROUND: Despite advances in revascularization following extremity vascular injury, the relationship between time to restoration of flow and functional limb salvage is unknown. The objectives of this study are to describe a large animal survival model of hind limb ischemia/reperfusion and define neuromuscular recovery following increasing ischemic periods. METHODS: Sus scrofa swine (N = 38; weight, 87 ± 6.2 kg) were randomized to iliac artery occlusion for 0 (Control), 1 (1HR), 3 (3HR), or 6 (6HR) hours, followed by vessel repair and 14 days of recovery. Additionally, one group underwent iliac artery division with no restoration of flow (Ligation), and one group underwent iliac artery exposure only without intervention (Sham). A composite physiologic measure of recovery (PMR) was generated to assess group differences over 14 days of survival. PMR included limb function (Tarlov score) and electrophysiologic measures (compound muscle action potential amplitude, sensory nerve action potential amplitude, and nerve conduction velocity). Using the PMR and extrapolating the point at which recovery following ligation crosses the slope connecting recovery after 3 and 6 hours of ischemia, an estimate of the ischemic threshold for the hind limb is made. These results were correlated with peroneus muscle and peroneal nerve histology. RESULTS: Baseline physiologic characteristics were similar between groups. Neuromuscular recovery in groups with early restoration of flow (Control, 1HR, 3HR) was similar and nearly complete (92%, 98%, and 88%, respectively; P > .45). While recovery was diminished in both 6HR and Ligation, Ligation, rather than repair, exhibited greater recovery (68% vs 53%; P < .05). These relationships correlated with the pathologic grade of degeneration, necrosis, and fibrosis (P < .05). The PMR model predicts minimal and similar persistent loss of function in groups undergoing early surgical restoration of flow (Control 8%, 1HR 1%, 3HR 12%; P > .45). In contrast, the Ligation group exhibited the greatest degree of injury early in the reperfusion period, followed by more complete recovery and at a faster rate than 6HR. Extrapolating from the PMR the point at which Ligation (68% recovery) crosses the slope connecting 3 hours (84% recovery) and 6 hours (53% recovery) of ischemia estimates the ischemic threshold to be 4.7 hours. Restoration of flow at ischemic intervals exceeding this are associated with less physiologic recovery than ligation. CONCLUSION: In this model, surgical and therapeutic adjuncts to restore extremity perfusion early (1-3 hours) after extremity vascular injury are most likely to provide outcomes benefit compared with delayed restoration of flow or ligation. Furthermore, the ischemic threshold of the extremity after which neuromuscular recovery is significantly diminished is less than 5 hours. Additional studies are necessary to determine the effect of other factors such as shock or therapeutic measures on this ischemic threshold.

A large animal survival model (Sus scrofa) of extremity ischemia/reperfusion and neuromuscular outcomes assessment: a pilot study.

BACKGROUND: Extremity ischemia/reperfusion has been studied mostly in small-animal models with limited characterization of neuromuscular or functional outcome. The objective of this experiment was to report a large-animal survival model of extremity ischemia/reperfusion using circulating, electromyographic (EMG), gate, and histologic measures of injury and limb recovery. METHODS: Sus scrofa swine (n = 6; mean, 83 kg) were randomized to iliac artery occlusion for 0 (control), 1 (1 HR), 3 (3 HR), or 6 (6 HR) hours. Restoration of flow after a standard large-vessel reconstructive technique (thrombectomy, heparin irrigation, and patch angioplasty) was performed in each of the control, 1HR, 3HR, and 6HR animals, whereas one animal had iliac artery segment excision with no restoration (NR) of axial flow. One animal had operative exposure but no intervention on the iliac artery (sham). Animals were recovered and closely monitored for 2 weeks. Indicators of ischemia/reperfusion and functional recovery, including circulating markers, EMG measures (complex motor action potential), and Tarlov gate scoring (0-4; 0, insensate/paralyzed to 4, normal posture and no gait abnormality) were measured at 24 hours and 72 hours and 7 days and 14 days. Muscle (peroneus) and nerve (peroneal) were collected during necropsy at 14 days to assess gross and histologic changes. Duplex ultrasound was performed serially during the recovery period to confirm patency of vascular reconstruction. RESULTS: There were no deaths or failures of vascular reconstruction. Control had a Tarlov score of 4 and normal EMG measures at each point during recovery (same as sham). Tarlov scores at 1, 3, and 14 days recovery in each of the animals were as follows: 1HR: 3, 3, and 4; 3HR: 1, 2, and 4; 6HR: 1, 2, and 3; and NR: 1, 2, and 4. Complex motor action potential as a percentage of baseline at 1, 2, and 14 days recovery was as follows: 1HR: 56%, 55%, and 84%; 3HR: 9%, 8%, and 57%; 6HR: 5%, 5%, and 16%; and NR: 22%, 28%, and 33%. Muscle and nerve histology was the same in sham, control, and 1HR animals. Moderate degeneration and necrosis was observed in peroneus muscle of the 3HR animals. The peroneal nerve in 3HR demonstrated minimal Wallerian degeneration. Severe necrosis was present, as was minimal regeneration, and peroneal nerve demonstrated moderate Wallerian degeneration in 6HR. CONCLUSION: This study reports a new large-animal survival model of extremity ischemia/reperfusion using circulating, functional, and histologic markers of neuromuscular recovery. Findings provide insight into an extremity ischemic threshold after which functional neuromuscular recovery is lost. Additional study is necessary to define this threshold and factors that may move it to a more or less favorable position in the setting of extremity injury.

Outcomes of selective tibial artery repair following combat-related extremity injury.

OBJECTIVE: Selective tibial revascularization refers to the practice of vessel repair vs ligation or observation based on factors observed at the time of injury. Although commonly employed, the effectiveness of this strategy and its impact on sustained limb salvage is unknown. The objective of this study is to define the factors most relevant in selective tibial artery revascularization and to characterize limb salvage following tibial-level vascular injury. METHODS: The cohort of active-duty military patients undergoing infrapopliteal artery repair comprises the tibial Bypass group. A similarly injured cohort of patients that did not undergo operative vascular intervention (No Bypass group) was identified. All tibial vessel injuries were documented by angiography. Data were compiled via medical records and patient interview. The primary outcome measure was failure of limb salvage. Multivariate regression was performed to identify factors associated with revascularization and to describe factors associated with amputation. RESULTS: Between March 2003 and September 2008, 135 of 1332 patients with battle-related vascular injuries had documented tibial vessel disruption or occlusion. Of these, 104 were included for analysis. Twenty-one underwent autologous vein bypass at the time of injury (Bypass group), and the remaining 83 patients were managed without revascularization (No Bypass group). Mean follow-up (39 vs 41 months; P = .27), age (25 vs 27 years; P = .66), and mechanism of injury (88% vs 92% penetrating blast; P = .56) were similar, but the No Bypass group had higher Injury Severity Scores (ISS; 16.3 vs 11.7; P < .01). Injury characteristics, including Gustilo III classification (49% vs 43%; P = .81) and nerve injury (55% vs 53%; P = 1.0), were similar. Subjects were more likely to receive tibial bypass with an increasing number of tibial vessel occlusions and documented ischemia on initial exam. However, of the 23 in the No Bypass group with initially unobtainable Doppler signals, 17 (74%) regained pedal flow following resuscitation and limb stabilization. Amputation rates were similar (23% vs 19%; P = .79), but the prevalence of chronic limb pain was lower in the Bypass group (10% vs 30%, respectively; P = .08). Cox regression analysis of amputation-free survival demonstrated an association between mangled extremity severity score >5 (hazard ratio [HR], 2.7; P = .01) and amputation. CONCLUSIONS: This report provides outcomes data for wartime tibial vascular injury, which supports a selective approach to tibial artery revascularization. Clinical factors such as ISS and degree of ischemia guide which patients are best suited for tibial vascular repair, while injury-specific characteristics are associated with amputation regardless of revascularization status.

Temporal changes of aortic neck morphology in abdominal aortic aneurysms.

OBJECTIVES: This study characterized temporal changes in the infrarenal aortic aneurysm neck in patients with small, untreated abdominal aortic aneurysms (AAA). METHODS: Patients with infrarenal AAA who had contrast-enhanced computed tomography (CT) scans separated by >6 months were identified and their images reviewed. Infrarenal neck diameter and length were measured along with aneurysm diameter. Comparisons between the interval CT scans were made and analysis of factors affecting neck changes performed. RESULTS: Sixty patients met inclusion criteria with an imaging interval of 3.8 years (median, 3.4 years; range, 0.75-9.6 years). During the interval, there was an increase in proximal and distal neck diameters of 1.1 mm (SD, 2.2) (0.28 mm/y) and 1.0 mm (SD, 3.0) (0.26 mm/y), respectively. During the same interval, the neck length decreased by 4 mm (SD, 11) (1 mm/y). A neck length of <15 mm was present in 10 patients (17%) at the initial imaging. Four of the remaining 50 patients experienced an interval decrease in neck length to <15 mm, all of whom had initial lengths of 15 to 20 mm. Medications had no association with changes in neck morphology; however, diabetes correlated with a slower rate of neck shortening (P = .001). CONCLUSION: The natural history of the aneurysm neck is one of expansion and shortening that will not affect most patients under surveillance. Patients with marginal neck lengths (range, 15-20 mm) at the initial imaging are more likely to experience loss of neck length that may negatively affect endovascular suitability.

Wartime thoracic injury: perspectives in modern warfare.

BACKGROUND: Thoracic injury represents a major source of combat morbidity and mortality. The overall killed-in-action rate has decreased, whereas the died-of-wounds rate has increased; the creation of the Joint Theater Trauma Registry allows for improved documentation. This report seeks to provide a realistic contemporary look at thoracic injury sustained by military forces and civilian casualties during the current wartime experience. METHODS: The Joint Theater Trauma Registry was queried between 2002 and 2008. Patients receiving treatment for thoracic injuries were identified using International Classification of Diseases, 9th edition, diagnosis and procedure codes. All US soldiers, coalition forces, and local civilians were included in the analysis. RESULTS: There were 33,755 casualties identified during the study period, of which 1,660 patients (4.9%) sustained thoracic injury. Blast mechanism was the most prominent mode of injury, accounting for 45.8%. The mean Injury Severity Score in this cohort of patients was 14.9. A total of 4,232 procedures were performed, resulting in an average of 2.5 thoracic procedures per patient. Fifty percent of casualties were civilian, and 34% were US troops, with the remainder occurring in coalition forces. Overall mortality was 12%. CONCLUSIONS: This report provides a realistic account of current wartime thoracic injury. In contrast to previous wars, the majority of thoracic injury is secondary to blast injury as opposed to penetrating trauma, and the resultant mortality rate is higher. This report breaks down thoracic injuries to both US troops and civilian personal and provides realistic expectations for thoracic injury during future combat planning.

A national survey of evolving management patterns for vascular injury.

BACKGROUND: The modern era has witnessed an increase in endovascular techniques used by physicians to treat vascular injury and age-related disease. As a consequence, the number of open vascular operations available for general surgical education has decreased dramatically. This changing paradigm threatens competence in vascular injury management achieved during surgical residency. The objective of this study is to sample perceptions on vascular injury treatment in the United States to highlight the need for planning for this important tenet of surgical education. METHODS: An electronic survey was extended to board-certified surgeons through 3 professional societies, the Peripheral Vascular Surgery Society (PVSS), the Eastern Association for the Surgery of Trauma (EAST), and the American College of Surgeons (ACS). RESULTS: A total of 520 respondents were self-categorized as trauma (59%; n = 307), vascular (17%; n = 90), or general (19%; n = 99) surgeons. Respondents reported that general surgeons currently manage less than 10% of vascular injuries at their respective institutions. A 2.5-fold increase in endovascular treatment of vascular injury during the past decade was reported with interventional radiologists now involved in the management of up to 25% of injuries. Few general or trauma surgeons surveyed possessed a catheter-based skill set, although 38% of trauma surgeons expressed great interest in endovascular training. Additionally, a cadre of vascular surgeons (67%) affirmed a commitment to teaching vascular injury management. CONCLUSIONS: The results of this study confirm a diminished role for non-fellowship-trained surgeons in managing vascular injury. Despite an increased acceptance of endovascular techniques to manage trauma, general and trauma surgeons do not possess the skill set. Collaboration between surgical communities will be especially important to maintain high standards in vascular injury management.