Evaluation of factors associated with limb thrombus formation after endovascular aortic aneurysm repair.

BACKGROUND: Limb thrombus formation is a complication that can occur after endovascular aortic repair (EVAR), and its clinical significance has continued to be debated. Our objective was to report the incidence of limb thrombus after EVAR and determine the association of specific demographic, anatomic, and/or graft variables. METHODS: A retrospective analysis of EVAR patients at a single tertiary center between January 2010 and December 2018 was performed to determine the limb thrombus rate. Demographic, graft, and anatomic variables were analyzed for an association with limb thrombus. RESULTS: A total of 301 patients were included. The average follow-up was 27.6 ± 4.9 months. The mean age was 76.5 ± 0.5 years, and 85% were men. Limb thrombus occurred in 22 patients (7.3%). Of these 22 patients, 11 (50.0%) had had occlusive limb thrombus, 14 (63.6%) were symptomatic, and 17 (77.3%) had required intervention. The patients with limb thrombus were younger (69.8 ± 1.3 years vs 77.1 ± 0.5 years; P < .0001) and more likely to be smokers (10.2% vs 5.2%; P = .10). The incidence of limb thrombus with the Alpha graft (10.7%; Cook Medical Inc, Bloomington, IN) was compared with that with non-Cook grafts (4.0%; P = .07). The average common iliac artery diameter for patients with and without limb thrombus was 14.1 mm and 16.1 mm, respectively (P < .01). Right-sided limb thrombus was more likely in smaller right iliac arteries (14.7 ± 0.9 cm vs 17.0 ± 0.6 cm; P < .05), with a similar finding on the left (13.6 ± 0.9 cm vs 15.2 ± 0.4 cm; P = .13). Unilateral limb thrombus was almost twice as likely on the main body side than on the contralateral side (11 vs 6). Limb thrombus was not associated with aortoiliac disease (odds ratio [OR], 1.31; 95% confidence interval [CI], 0.37-4.62), limb extension (OR, 0.47; 95% CI, 0.06-3.62), or nonmatching limb heights (OR, 1.36; 95% CI, 0.54-3.43). Limb thrombus was also not associated with increased 30-day mortality (P > .05). CONCLUSIONS: Limb thrombus formation is a complication that can occur after EVAR (7.3%). In our study, limb thrombus was seen more frequently in younger patients and those who smoked. Cook Alpha grafts had a thrombus formation rate of 10.7%, which was not significantly higher than that with other brands. Limb thrombus was more likely in smaller iliac arteries and on the main body side.

Surgical Management of Delayed Brachial Plexopathy After Clavicle Nonunion.

SUMMARY: Brachial plexopathy after conservative therapy or surgical treatment of clavicular fractures is an uncommon, yet serious complication that is associated with compression of the brachial plexus or the subclavian artery and vein because they traverse through the thoracic outlet. Surgical decompression of the brachial plexus is the recommended treatment if this condition is to occur. Although there are multiple reports of these cases in the literature, at present, there are no clear guidelines for their management. We are highlighting an institutional management algorithm, illustrated by a small retrospective case series, that uses a multidisciplinary approach in an effort to minimize complications associated with the management of clavicle nonunion.

Evaluation of Aortic Zone 2 Proximal Landing Accuracy During Thoracic Endovascular Aortic Repair Following Carotid-Subclavian Revascularization.

BACKGROUND: Adequate seal for thoracic endovascular aortic repair (TEVAR) commonly requires landing in zone 2, but can prove to be challenging due to the tortuous and angulated anatomy of the region. OBJECTIVES: Our objective was to determine the proximal landing accuracy of zone 2-targeted TEVARs following carotid-subclavian revascularization (CSR) and its impact on clinical outcomes. METHODS: Retrospective review of patients that underwent CSR for zone 2 endograft delivery at a tertiary institute between January 2008 and March 2018 was conducted. Technical outcomes were assessed by examining the incidence of intraoperative corrective maneuvers, 1a endoleaks and reinterventions. Distance to target and incidence of LSA stump filling were examined as radiographic markers of landing accuracy. RESULTS: Zone 2-targeted TEVAR with CSR was performed in 53 patients for treatment of dissections (49%), aneurysms (30%) or trauma (21%). Nine (17%) cases required intraoperative corrective procedures: 5 (9%) proximal cuffs due to type 1a endoleak and 4 (8%) left common carotid artery (LCCA) stenting due to inadvertent coverage. Cases performed using higher resolution hybrid fluoroscopy machine compared to mobile C-arm were associated with increased proximal cuff use (OR 8.8; 95% CI 1.2-62.4). Average distance between the proximal edge of the covered graft to LCCA was 8 ± 1 mm and larger distances were not associated with higher rates of 1a endoleak. Twenty-eight (53%) cases of antegrade LSA stump filling were noted on follow-up imaging, but were not associated with higher rates of reinterventions (OR 0.8, 95% CI [0.2-4.6]). Three (6%) patients had a stroke within 30 days and 4 (8%) patients expired within 1 month. Intraoperative corrective maneuvers, post-operative 1a endoleak and reinterventions were not associated with higher rates of stroke or mortality. CONCLUSION: Using current endografts and imaging modalities, zone 2-targeted TEVARs have suboptimal technical accuracy.

Acute mesenteric ischemia leading to diagnosis of advanced spindle cell carcinoma of the lung.

Acute ischemic events secondary to pulmonary malignancy are rare. Those who present with acute peripheral arterial occlusions from malignant sources will typically have advanced pulmonary malignancy or myxomatous tumors. A 79-year-old woman had presented to Vancouver General Hospital with acute mesenteric ischemia. The pathology reports after embolectomy indicated cell morphology consistent with spindle cell carcinoma of the lung. Imaging investigations revealed a right upper lobe mass not present on chest imaging studies performed 14 months previously. The findings from the present report serves to remind us that acute ischemic events in the setting of no known history of malignancy or cardiac disease should prompt investigations into possible malignant sources.

An age-based comparison of fistula location, patency, and maturation for elderly renal failure patients.

OBJECTIVE: Current Kidney Disease Outcomes Quality Initiative guidelines do not incorporate age in determining autogenous arteriovenous hemodialysis access placement, and the optimal initial configuration in elderly patients remains controversial. We compared patency, maturation, survival, and complications between several age cohorts (<65 years, 65-79 years, >80 years) to determine whether protocols should be modified to account for advanced age. METHODS: All patients at two teaching hospitals undergoing a first autogenous arteriovenous access creation in either arm between 2007 and 2013 were retrospectively analyzed from a prospectively maintained database. Kaplan-Meier survival and Cox hazards models were used to compare access patency and risk factors for failure. RESULTS: There were 941 autogenous arteriovenous accesses (median follow-up, 23 months; range, 0-89 months) eligible for inclusion; 152 (15.3%) accesses were created in those >80 years, 397 (42.2%) in those 65 to 79 years, and 392 (41.8%) in those <65 years. Primary patencies in patients >80 years, 65 to 79 years, and <65 years were 40% ± 4%, 38% ± 3%, and 51% ± 3% at 12 months and 12% ± 5%, 13% ± 3%, and 27% ± 3% at 36 months (P < .001). Primary assisted patencies were 72% ± 4%, 70% ± 2%, and 78% ± 2% at 12 months and 52% ± 5%, 52% ± 3%, and 67% ± 3% at 36 months (P < .001). Secondary patencies were 72% ± 4%, 71% ± 2%, and 79% ± 2% at 12 months and 54% ± 5%, 55% ± 3%, and 72% ± 3% at 36 months (P < .001). Radiocephalic patencies were lowest among older cohorts; in those >80 years, 65 to 79 years, and <65 years, they were 65% ± 7%, 67% ± 4%, and 77% ± 3% at 12 months and 41% ± 8%, 51% ± 5%, and 68% ± 4% at 36 months (P = .019). Secondary brachiocephalic access patencies in these cohorts were 78% ± 5%, 80% ± 3%, and 82% ± 3% at 12 months and 68% ± 7%, 66% ± 5%, and 77% ± 4% at 36 months (P = .206). Both the age groups 65 to 79 years and >80 years demonstrated superior brachiocephalic vs radiocephalic secondary patencies (P = .048 and P = .015, respectively); however, no differences between configuration and secondary patency were observed within the cohort <65 years. Radiocephalic access maturation failure at 12 and 24 months was 25% ± 3% and 29% ± 4% in those <65 years, 32% ± 3% and 39% ± 4% in those 65 to 79 years, and 40% ± 7% and 48% ± 8% in those >80 years (P = .006). Brachiocephalic access maturation failures were 17% ± 3% and 20% ± 3% at 12 and 24 months in those <65 years, 21% ± 3% and 25% ± 4% in those 65 to 79 years, and 18% ± 5% and 21% ± 5% in those >80 years (P = .740). On multivariate analysis, coronary disease, female sex, previous ipsilateral or bilateral catheters, radiocephalic configuration, and age >65 years were associated with secondary patency loss. CONCLUSIONS: Patients aged 65 to 79 years and >80 years had inferior primary, primary assisted, and secondary patency and maturation compared with those <65 years. When stratified by configuration, radiocephalic accesses demonstrated lower patency and maturation compared with brachiocephalic accesses for patients aged 65 to 79 years and >80 years and were an independent predictor of secondary patency loss.

A comparison of revision using distal inflow and distal revascularization-interval ligation for the management of severe access-related hand ischemia.

OBJECTIVE: Access-related hand ischemia (ARHI) is a potentially limb-threatening complication of arteriovenous access for dialysis. The distal revascularization-interval ligation (DRIL) and revision using distal inflow (RUDI) procedures both allow treatment of ischemic symptoms while maintaining fistula patency. Although outcomes with the DRIL are well established, experience with the RUDI for ARHI remains preliminary. We compared outcomes in these procedures with respect to cumulative patency, resolution of symptoms, and patient survival. METHODS: A large, prospectively maintained database was used to identify all patients after autogenous arteriovenous fistula construction at two hospitals between 2005 and 2015. Patients with severe Society for Vascular Surgery grade 3 ARHI were included for analysis. RESULTS: A total of 2035 autogenous accesses were created during the study period, and 58 (3%) developed grade 3 ARHI. Of this cohort, RUDI was performed in 20 and DRIL in 21. The indication for intervention was tissue loss (61%) or ischemic rest pain (39%). Mean age was 57.5 years, and 54% of patients were female. Most patients had diabetes (86%) and symptomatic peripheral arterial disease (63%). The mean preoperative digital-brachial index was 0.25 ± 0.12. There were no preoperative differences in patient comorbidities between the RUDI and DRIL cohorts. Primary patency between the RUDI and DRIL cohorts at 12 months (58% ± 11% vs 55% ± 12%) and 36 months (51% ± 12% vs 41% ± 12%) were similar (P = .841). Cumulative secondary patency at 12 months (84% ± 8% vs 94% ± 6%) and 36 months (78% ± 9% vs 86% ± 9%) showed no significant difference (P = .398). Resolution of ischemic symptoms, including resolution or improvement in pain or healing of ischemic ulcers or amputations, occurred in 90% with RUDI and in 81% with DRIL (P = .131). Survival for patients who underwent RUDI or DRIL procedures at 1 and 3 years was 85% vs 86% (P = .948) and 55% vs 49% (P = .278). CONCLUSIONS: In this preliminary study, the RUDI demonstrated similar patency, symptom resolution, and survival compared with the DRIL for patients with severe ARHI. All-cause mortality after any procedure for severe steal syndrome is high, and the particular intervention for management of steal must account for anatomic-, patient-, and disease-related considerations.

Using a Chimney to Make a Sandwich: Salvage of a Multibranched Thoracoabdominal Aortic Endograft with a Type IIIb Endoleak.

BACKGROUND: The advent of branched and fenestrated aortic endografts has facilitated the treatment of increasingly complex aortic pathology. The management of complications and endoleaks involving the branches and fenestrations of these grafts represents an increasingly significant clinical and technical challenge. METHODS: A 79-year-old woman developed a rare type IIIb endoleak from a tear in the graft fabric immediately posterior to the celiac axis branch 3 years after the placement of an off-the-shelf branched endograft for a type II thoracoabdominal aortic aneurysm. The patient presented urgently with abdominal pain and a maximal aneurysm diameter of 15.3 cm. RESULTS: The operative plan was to create a chimney graft completely within the original branched endograft to cover the defect and maintain celiac branch flow. The celiac trunk was accessed from a left axillary approach and access for the main endograft body was achieved via the left femoral artery. Two balloon-expandable covered stents were deployed from the celiac branch extending into the main endograft as a chimney and molded to 2 aortic extension cuffs to cover the fabric defect. The resultant configuration was a modified-sandwich graft within the original stent graft and resulted in successful exclusion of the endoleak. Postoperative imaging at 1, 6, and 12 months has demonstrated continued patency of the celiac trunk, no further endoleak, and a 16-mm reduction in aneurysm size. CONCLUSIONS: The chimney technique was successfully applied as an endovascular option to salvage a multibranched endograft with a significant and anatomically unfavorable defect. Careful follow-up and additional clinical study are required to clarify the role of off-the-shelf solutions in complex endoleak management.

A practical guide to magnetic resonance vascular imaging: techniques and applications.

Magnetic resonance angiography is a technique used to image both central and peripheral arteries using contrast and noncontrast techniques. These techniques are similar in that a bright signal, which appears white within blood vessels, is generated and the background tissues, veins, and stationary tissues are dark. This allows for assessment of anatomy and vascular disease. Extracellular gadolinium-based contrast agents allow for excellent visualization of both central and peripheral arteries. Acquiring images during first pass is required for high-contrast images within arteries, thereby limiting contamination with contrast enhancement of veins and soft tissue. Contrast-enhanced techniques using time-resolved angiography and blood pool contrast agents minimize this temporal limitation. Noncontrast techniques eliminate the uncommon but potentially fatal complications associated with gadolinium contrast agents, such as nephrogenic systemic fibrosis. These techniques including phase contrast and time-of-flight sequences have inferior contrast resolution compared with contrast-enhanced techniques and are susceptible to artifacts, which can limit interpretation. The advantage, however, is the ability to assess vascular disease in patients with severe renal failure without the added risks of gadolinium contrast media. The aim of this review is to outline the different techniques available for imaging both the arterial and venous systems, their advantages and disadvantages, and the indications in vascular disease.

Development of a comprehensive vascular skills assessment for surgical trainees.

BACKGROUND: Although vascular skills are important to general surgeons, vascular surgery has become a separate specialty, and therefore, there may be an erosion of vascular skills acquired by general surgical trainees. The purpose of this study was to develop a reliable and valid comprehensive vascular skills assessment (CVSA) of both knowledge and technical skills. METHODS: Twenty-four of 38 general surgical residents at the University of British Columbia completed a two-part CVSA consisting of a written examination and a series of 4 technical stations in a skills laboratory. Technical performance was rated using validated scales. RESULTS: The mean overall CVSA score was 50%. The CVSA demonstrated construct validity, with improvement in scores with increasing postgraduate year level (P = .01). The overall reliability (Cronbach's alpha) was .90. CONCLUSIONS: The CVSA developed in this study is a comprehensive assessment of vascular skills that is both valid and reliable. It offers an objective and feasible assessment of general surgical trainees' vascular skills.

Acidosis augments myogenic constriction in rat coronary arteries.

The myogenic response is a process by which blood vessels autoregulate vascular smooth muscle tone in response to changes in transmural pressure. It is characterized by vessel contraction or dilation with increased or decreased pressure, respectively. We sought to identify whether acidosis impacts the myogenic response in rat coronary resistance arteries. Ventricular septal arteries were isolated from male Sprague-Dawley rats and mounted on a pressure myograph. The myogenic response was assessed by measuring the arterial diameter at pressures of 10-120 mm Hg. The fluorescence indicators 2',7'-bis-(carboxyethyl)-5(and-6)-carboxyfluorescein and Fura-2 were utilized to measure intracellular pH (pH(i)) and intracellular free calcium concentration ([Ca(2+)](i)), respectively. A decrease in the extracellular pH (pH(o)) from 7.4 to 6.9 produced a fall in pH(i) and an increase in the myogenic response. Under nominally HCO (3) (-) /CO(2)-free conditions at a constant pH(o), blockade of the sodium-hydrogen exchanger with HOE694 also resulted in a fall in pH(i) and a similar enhancement of myogenic activity. Concentration response curves were constructed to measure the potencies of the HOE694 effects: the EC(50) was 34 microM for the pH(i) change and 19 microM for vessel constriction. Apparent [Ca(2+)](i) remained unchanged during HOE694-induced intracellular acidification. Furthermore, in the presence of HCO (3) (-) , HOE694 did not markedly affect pH(i) and vascular tone remained unaltered. Our data demonstrate that acidosis augments myogenic constriction of rat coronary arteries. These effects are due to a fall in pH(i) consequent upon the reduction in pH(o) and may reflect an increased myofilament [Ca(2+)](i) sensitivity within vascular smooth muscle cells.

Intra-abdominal complications after surgical repair of small bowel injuries: an international review.

BACKGROUND: The ideal method of repairing serious small bowel injuries remains unknown. Prior reports suggest a higher rate of enteric anastomotic-related complications (EACs) with stapled posttraumatic bowel anastomosis but did not specifically focus on the small bowel or clarify fully the actual anastomotic construction. METHODS: This was a retrospective review of patients requiring surgical repair of small bowel perforations at a Level I urban American center (Detroit Receiving Hospital [DRH]) and a Canadian provincial trauma center (Vancouver Hospital and Health Sciences Center [VHHSC]). All patients requiring a primary repair and/or resection were included. Anastomoses were hand-sewn, stapled, or combined stapling and sewing with mucosal inversion. Leaks, anastomotic fistulae, and intra-abdominal abscesses were considered specific EACs. A sample size of 53 per group was obtained to detect a 17% difference at alpha = 0.05 (one-sided) and beta = 0.2. RESULTS: Full-thickness small bowel injuries were repaired in 232 patients (DRH, 165; VHHSC, 67). Injuries were penetrating at DRH (91.5%) and blunt at VHHSC (65.7%). Anastomotic repairs in 127 patients (158 anastomotic repairs [DRH, 113; VHHSC, 55]) were 64 (40.5%) stapled, 38 (24.1%) hand-sewn, and 56 (35.4%) combined. Also, 105 patients had 349 primary closures of an injury. Overall, there were 24 EACs. After anastomosis, there were 11 intra-abdominal abscesses: 6 after stapling, 3 after being sewn, and 2 after a combined construction. There were four small bowel anastomotic fistulae: three after stapled-only anastomosis and one after hand-sewing. After enteroenterostomy, the EAC rate was 10.2% per patient, or 8.4% per anastomosis. After primary repairs, one patient had an anastomotic fistula, which closed spontaneously, and 11 had intra-abdominal abscesses, yielding an EAC rate of 10.6% per patient or 3.4% per repair. A primary repair was significantly less likely to be associated with an EAC than any anastomosis (p = 0.035). No method of anastomosis was statistically safer in relation to EACs, whether analyzed by patient, by anastomosis, or by considering primarily either the use of a linear stapler or the principle of inverting the mucosal approximation. Only damage control procedures and associated pancreaticoduodenal injuries were identified as statistically significant predictors using multiple logistic regression analysis. CONCLUSION: Anastomotic complications after enteroenterostomy or primary repair for trauma are uncommon regardless of the technique, but surgeons must be especially cautious during or after damage control. Primary repairs are desirable, but when anastomosis is unavoidable, the method of repair should reflect that with which the surgeon is the most comfortable.