Adham N. Abou Ali

Catheter Interventions for Pulmonary Embolism: Are They Really that Safe?

Catheter-directed interventions (CDI) are increasingly used for the treatment of acute pulmonary embolism (PE), despite the scarcity of comparative prospective data. Although systemic thrombolysis improves the PE hemodynamic profile, this comes at the cost of a high major bleeding risk assumed to be negligible if CDIs are used. Mostafa et al are to be commended for thismuch needed review of the studies that summarize the technologies available for CDIs and the complications associated with this technique. The purpose of this letter is to call attention to the safety profile of CDIs. The conclusion of Mostafa et al that the pooled major bleeding complication rate of ultrasound assisted thrombolysis (USAT) is “below 1%” is a significant underestimation of the published data, given the variable definition of major bleeding as reported in each study. To be consistent with the reporting of major bleeding, a Prospective, Single-arm, Multi-center Trial of EkoSonic Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (SEATTLE II) study reported a 15/ 150 (10.0%) and not 1/150 (0.7%) major bleeding rate. Apart from the 1 patient requiring vasopressor support,

Early carotid endarterectomy performed 2 to 5 days after the onset of neurologic symptoms leads to comparable results to carotid endarterectomy performed at later time points

Background: Timing of carotid endarterectomy (CEA) after onset of neurologic symptoms remains controversial. We assessed the association of CEA timing with postoperative outcomes. Methods: The Vascular Study Group of New England (VSGNE) database (2003–2014) was queried to identify CEA performed for symptomatic carotid stenosis during the same hospitalization. Cases were divided into four groups based on the time from onset of neurologic symptoms to CEA: group I, <2 days; group II, 2 to 5 days; group III, ≥6 days; and group IV, same‐day CEA. The χ2 test and t‐test were used to compare demographics, medical history, modified Rankin scores, and outcomes (30‐day postoperative death, stroke, myocardial infarction, and aggregate events [stroke/myocardial infarction]). Multivariable logistic regression was used to compare the association of time to surgery with outcomes while adjusting for confounding variables. Kaplan‐Meier and Cox proportional hazards regression analyses were performed at 1 year to evaluate survival and stroke rates between the groups. Results: There were 989 of 14,864 VSGNE CEA cases that fit the inclusion criteria. The frequency of cases was highest in group II (36.6%), followed by groups I (31.9%), III (18.9%), and IV (12.4%). Age, gender, and comorbidity compositions were similar between groups, although group III had the highest rates of diabetes mellitus, coronary artery disease, coronary artery bypass graft procedures, congestive heart failure, and American Society of Anesthesiologists class 4 and the highest modified Rankin score (P < .05). Stroke rates were highest in group I (7.3%; P = .016), whereas group III had the highest rate of discharges to nursing facilities (37.2%; P < .001); other adverse outcomes were comparable among groups. CEAs in group I had significantly increased adjusted odds of stroke; adverse outcomes of CEAs in groups II and III were comparable to those in group IV. Conclusions: Our results suggest that CEAs performed 2 to 5 days after a neurologic event have similar outcomes to CEAs performed ≥6 days later. Early CEA should be considered an area for quality improvement among these patients.

Role of Venous Stenting for Iliofemoral and Vena Cava Venous Obstruction

Venous stenting for CVD is being increasingly used as more evidence accumulates supporting the open vein hypothesis and supporting the safety, efficacy, and durability of these interventions. As such, they can be offered to patients with advanced age and complex comorbidities. Future studies should focus on reporting outcomes specific to the underlying venous pathologic condition (thrombotic vs nonthrombotic and acute vs chronic) to provide better evidence for stenting in CVD, and the outcomes of new stent design with dedicated venous indications.

Catheter-Directed Thrombolysis of Pulmonary Embolism

The treatment of intermediate- and high-risk pulmonary embolism (PE) is experiencing dramatic changes given the ineligibility of many patients for systemic thrombolysis and the potential associated complications. Catheter-directed interventions (CDIs) are increasingly performed for acute PE as they are presumed to provide similar therapeutic benefits compared to systemic thrombolysis while decreasing the dose of thrombolytic required and the associated risks. This chapter reviews catheter-directed interventions for acute PE including the indications, available techniques, clinical effectiveness, complication rates, and long-term outcomes.

Endovascular Treatment of Pulmonary Embolism

Acute pulmonary embolism can result in high rates of morbidity and mortality. Traditional treatments for pulmonary embolism such as systemic thrombolysis and surgical thrombectomy are associated with high complication rates. Advances in endovascular therapy have allowed for usage of minimally invasive approaches such as catheter-directed thrombolysis, aspiration thrombectomy, and pharmacomechanical thrombectomy in the treatment of acute pulmonary embolism. These therapies may provide similar hemodynamic improvement to traditional techniques while decreasing risks of serious complications. Acute pulmonary embolism is classified into low, intermediate, and high-risk presentations based on the presence or absence of hemodynamic instability, clinical risk factors, and biomarkers or imaging evidence of right ventricular dysfunction. Patients with high and intermediate-high risk presentations may benefit from intervention, but the risks of complications including intracranial hemorrhage must be taken into account when determining the type of intervention. Catheter-directed interventions have demonstrated good clinical success and excellent published safety profiles, but head-to-head comparisons of different interventional techniques have not been well studied. Further study of catheter-directed interventions and their effect on short- and long-term physiologic, functional, and quality-of-life outcomes is needed.

Outcomes of infrageniculate retrograde versus transfemoral access for endovascular intervention for chronic lower extremity ischemia

Objective: Retrograde infrageniculate access is an alternative treatment strategy for patients who have failed to respond to antegrade endovascular intervention. This study compares the outcomes of infrageniculate retrograde arterial access with the conventional transfemoral access for the endovascular management of chronic lower extremity ischemia. Methods: This was a retrospective single‐center review of retrograde endovascular intervention (REI) from 2012 to 2016. Indications for intervention, comorbidities, complications, procedural success, limb outcomes, and mortality were analyzed. Technical failure was defined as the inability to complete the procedure because of failed access or unsuccessful recanalization. Infrageniculate access and transfemoral access were obtained with ultrasound or angiographic roadmap guidance. Patency rates were calculated for technically successful interventions. Results: There were 47 patients (85% presenting with critical limb ischemia) who underwent sheathless REI after failed antegrade recanalization of TransAtlantic Inter‐Society Consensus class D infrainguinal lesions, whereas 93 patients (83% with critical limb ischemia) underwent standard transfemoral access. There were 16 (34%) femoropopliteal, 14 (30%) tibial, and 17 (36%) multilevel interventions in the retrograde group compared with 41 (41%) femoropopliteal, 20 (20%) tibial, and 39 (39%) multilevel interventions in the transfemoral group. Access sites for the retrograde group included the dorsalis pedis (26%), midcalf peroneal (24%), anterior tibial (22%), posterior tibial (26%), and popliteal (2%) arteries. Overall technical success was achieved in 57% of the retrograde group compared with 78% of the transfemoral group. Mean follow‐up was 20 months (range, 1‐45 months). There were no significant differences in the primary patency rates between the two groups at 1 year and 2 years. The primary assisted patency rates were significantly better in the transfemoral group at 1 year (66% vs 46%; P = .031) and 2 years (56% vs 29%; P = .031). The secondary patency rates were higher in the transfemoral group at 1 year (93% vs 83%; P = .079) and 2 years (91% vs 76%; P = .079), although this did not reach statistical significance. The rate of reintervention was 41% for the retrograde group vs 40% for the transfemoral group. Most of the reinterventions (70% in the retrograde group and 61% in the transfemoral group) were endovascular interventions for a restenosis or occlusion. Conclusions: Infrageniculate access for REI can result in primary patency rates similar to those of antegrade interventions and does not compromise the access site. Technical failure is high in this initial experience and is mostly due to failed recanalization. Limb salvage may be achieved after technical failure with either repeated antegrade intervention or surgical bypass.

Immediate-access grafts provide comparable patency to standard grafts, with fewer reinterventions and catheter-related complications

Background No independent comparisons, with midterm follow‐up, of standard arteriovenous grafts (SAVGs) and immediate‐access arteriovenous grafts (IAAVGs) exist. The goal of this study was to compare “real‐world” performance of SAVGs and IAAVGs. Methods Consecutive patients who underwent placement of a hemodialysis graft between November 2014 and April 2016 were retrospectively identified from the electronic medical record and Vascular Quality Initiative database at two tertiary centers. Only primary graft placements were included for analysis. Patients were divided into two groups based on the type of graft implanted. Patients’ comorbidities, graft configuration, operative characteristics, and follow‐up were collected and analyzed with respect to primary and secondary patency. Additional outcomes included graft‐related complications, time to first cannulation, time to tunneled catheter removal, catheter‐related complications, and overall survival. Patency was determined from the time of the index procedure; χ2, Kaplan‐Meier, and Cox regression analyses were used, with the P value set as significant at < .05. Results There were 210 grafts identified, 148 SAVGs and 62 IAAVGs. At baseline, the patients’ characteristics were similar between groups, except for a greater prevalence of preoperative central venous occlusions in the IAAVG group (16.3% vs 6.8%; P < .04). Of the IAAVG group, 50 were Acuseal (W. L. Gore & Associates, Flagstaff, Ariz) and 12 were Flixene (Atrium Medical Corporation, Hudson, NH). Primary patency was similar at both 1 year (SAVG, 39.4%; IAAVG, 56.7%; P = .4) and 18 months (SAVG, 29.0%; IAAVG, 43.7%; P = .4). Secondary patency was similar at 1 year (SAVG, 50.7%; IAAVG, 52.1%; P = .73) and 18 months (SAVG, 42.3%; IAAVG, 46.3%; P = .73). Overall survival was 48% at 24 months. IAAVG patients required fewer overall additional procedures to maintain patency (mean number of procedures, 0.99 for SAVGs vs 0.61 for IAAVGs; P = .025). There was no difference in occurrence of steal syndrome (SAVG, 6.8%; IAAVG, 8.1%; P = .74) or graft infection (SAVG, 19.0%; IAAVG, 12.0%; P = .276). Seventy‐five percent of all grafts were successfully cannulated, with shorter median time to first cannulation in the IAAVG group (6 days; interquartile range [IQR], 1‐19 days) compared with the SAVG group (31 days; IQR, 26‐47 days; P < .01). Of all pre‐existing catheters, 65.75% were removed, with a shorter median time until catheter removal in the IAAVG cohort at 34 days (IQR, 22‐50 days) vs 49 days (IQR, 39‐67 days) in the SAVG group (P < .01). Catheter‐related complications occurred less frequently in the IAAVG group (16.4% vs 2.9%; P < .045). Conclusions IAAVGs allow earlier cannulation and tunneled catheter removal, thereby significantly decreasing catheter‐related complications. Patency and infection rates were similar between SAVGs and IAAVGs, but fewer secondary procedures were performed in IAAVGs.

Vascular Shunts in Civilian Trauma

Experience with temporary intravascular shunts (TIVS) for vessel injury comes from the military sector and while the indications might be clear in geographically isolated and under resourced war zones, this may be an uncommon scenario in civilian trauma. Data supporting TIVS use in civilian trauma have been extrapolated from the military literature where it demonstrated improved life and limb salvage. Few non-comparative studies from the civilian literature have also revealed similar favorable outcomes. Still, TIVS placement in civilian vascular injuries is uncommon and by some debatable given the absence of clear indications for placement, the potential for TIVS-related complications, the widespread resources for immediate and definitive vascular repair, and the need for curtailing costs and optimizing resources. This article reviews the current evidence and the role of TIVS in contemporary civilian trauma management.

Contemporary Role of Embolization of Solid Organ and Pelvic Injuries in Polytrauma Patients

Abdominopelvic trauma (APT) remains a leading cause of morbidity and mortality in the 15- to 44-year-old age group in the Western World. It can be life-threatening as abdominopelvic organs, specifically those in the retroperitoneal space, can bleed profusely. APT is divided into blunt and penetrating types. While surgery is notably considered as a definitive solution for bleeding control, it is not always the optimum treatment for the stabilization of a polytrauma patient. Over the past decades, there has been a shift toward more sophisticated strategies, such as non-operative management of abdominopelvic vascular trauma for haemodynamically stable patients. Angiographic embolization for bleeding control following blunt and/or penetrating intra- and retroperitoneal injuries has proven to be safe and effective. Embolization can achieve hemostasis and salvage organs without the morbidity of surgery, and the development and refinement of embolization techniques has widened the indications for non-operative treatment in solid organ injury. Moreover, advances in computed tomography provided more efficient scanning times with improved image quality. While surgery is still usually recommended for patients with penetrating injuries, non-operative management can be effectively used as well as an alternative treatment. We review indications, technical considerations, efficacy, and complication rates of angiographic embolization in APT.