The Challenge of Treating Abdominal Aortic Aneurysms with Hostile Neck Anatomy: An Overview.

Hostile aortic neck anatomy challenges the outcomes of endovascular abdominal aortic aneurysm repair (EVAR). Besides reverting to open surgical repair (OSR), thoughtful endograft selection and a number of advanced endovascular techniques have been suggested as potential solutions for preventing proximal seal zone complications, improving EVAR durability, and preventing aneurysm-related death. Each technique is associated with advantages and limitations and there has not been a credible direct comparison amongst them in the form of a well-designed prospective trial. The not infrequent presence of multiple hostile anatomic characteristics further complicates decision making and challenges the surgeon's skills. This paper serves as an overview of hostile neck anatomy and its implications on EVAR. We provide a concise literature review with the purpose of outlining the treatment modalities and outcomes in this patient population.

Long-Term Outcomes of Open Versus Endovascular Treatment for Abdominal Aortic Aneurysm: Systematic Review and Meta-Analysis With Reconstructed Time-to-Event Data.

BACKGROUND: The advent of endovascular techniques has revolutionized the care of patients with uncomplicated abdominal aortic aneurysms. This analysis compares the overall survival and the freedom from reintervention rate between open surgical repair (OSR) and endovascular repair (EVAR) in patients undergoing elective abdominal aortic aneurysm (AAA) repair. METHODS: PubMed, Scopus, and Cochrane databases were searched for studies including patients who underwent either OSR or EVAR for uncomplicated AAA. All randomized controlled trials and propensity-score-matched cohort studies reporting on the outcomes of interest were considered eligible for inclusion. The systematic search of the literature was performed by 2 independent investigators in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We conducted 1-stage and 2-stage meta-analyses with Kaplan-Meier-derived time-to-event data and meta-analysis with a random-effects model. RESULTS: Thirteen studies met our eligibility criteria, incorporating 13 409 and 13 450 patients in the OSR and EVAR arms, respectively. Patients who underwent open repair had improved overall survival rates compared with those who underwent EVAR (hazard ratio [HR]=0.93, 95% confidence interval [CI]=0.88-0.98, p=0.004) during a mean follow-up of 53.8 (SD=29.8) months and this was validated by the 2-stage meta-analysis (HR=0.89, 95% CI=0.8-0.99, p=0.03, I2=62.25%). Splitting timepoint analysis suggested that EVAR offers better survival outcome compared with OSR in the first 11 months following elective intervention (HR=1.37, 95% CI=1.22-1.54, p<0.0001), while OSR offers a significant survival advantage after the 11-month timepoint and up to 180 months (HR=0.84, 95% CI=0.8-0.89, p<0.0001). Similarly, freedom from reintervention was found to be significantly better in EVAR patients (HR=1.28, 95% CI=1.14-1.44, p<0.0001) within the first 30 days. After the first month postrepair, however, OSR demonstrated higher freedom-from-reintervention rates compared with EVAR that remained significant for up to 168 months during follow-up (HR=0.73, 95% CI=0.66-0.79, p<0.0001). CONCLUSIONS: Despite the first-year survival advantage of EVAR in patients undergoing elective AAA repair, OSR was associated with a late survival benefit and decreased risk for reintervention in long-term follow-up. CLINICAL IMPACT: Open surgical repair for uncomplicated abdominal aortic aneurysm offers better long-term outcomes in terms of survival and freedom from reintervention rate compared to the endovascular approach but in the first year it carries a higher risk of mortality. The novelty of our study lies that instead of comparing study-level effect estimates, we analyzed reconstructed individual patient-level data. This offered us the opportunity to perform our analyses with mathematically robust and flexible survival models, which was proved to be crucial since there was evidence of different hazard over time. Our findings underline the need for additional investigation to clarify the significance of open surgical repair when compared to the latest endovascular devices and techniques within the evolving era of minimally invasive procedures.

Investigation of commonly used aortic aneurysm growth rate metrics: Comparing their suitability for clinical and research applications.

An aneurysm is a pathological widening of a blood vessel. Aneurysms of the aorta are often asymptomatic until they rupture, killing approximately 10,000 Americans per year. Fortunately, rupture can be prevented through early detection and surgical repair. However, surgical risk outweighs rupture risk for small aortic aneurysms, necessitating a policy of surveillance. Understanding the growth rate of aneurysms is essential for determining appropriate surveillance windows. Further, identifying risk factors for fast growth can help identify potential interventions. However, studies in the literature have applied many different methods for defining the growth rate of abdominal aortic aneurysms. It is unclear which of these methods is most accurate and clinically meaningful, and whether these heterogeneous methodologies may have contributed to the varied results reported in the literature. To help future researchers best plan their studies and to help clinicians interpret existing studies, we compared five different models of aneurysmal growth rate. We examined their noise tolerance, temporal bias, predictive accuracy, and statistical power to detect risk factors. We found that hierarchical mixed effects models were more noise tolerant than traditional, unpooled models. We also found that linear models were sensitive to temporal bias, assigning lower growth rates to aneurysms that were detected earlier in their course. Our exponential mixed model was noise-tolerant, resistant to temporal bias, and detected the greatest number of clinical risk factors. We conclude that exponential mixed models may be optimal for large studies. Because our results suggest that choice of method can materially impact a study's findings, we recommend that future studies clearly state the method used and demonstrate its appropriateness.

De novo acute type B aortic dissection in two patients with previous infrarenal endovascular aortic aneurysm repair with EndoAnchors.

Acute aortic dissection in the immediate postoperative period after endovascular abdominal aortic aneurysm repair (EVAR) has been linked to technical factors such as excessive endograft oversizing or aortic wall injuries during the procedure. In contrast, dissections that occur later are more likely to be de novo. Regardless of their etiology, aortic dissection can extend into the abdominal aorta, causing collapse and occlusion of the endograft with devastating complications. To the best of our knowledge, no studies have reported on aortic dissection in EVAR patients in whom EndoAnchors (Medtronic, Minneapolis, MN) had been used. We present two cases of de novo type B aortic dissection after EVAR with entry tears in the descending thoracic aorta. In both of our patients, the dissection flap appeared to stop abruptly at the site of endograft fixation with the EndoAnchors, suggesting that EndoAnchors might prevent the propagation of aortic dissection beyond the EndoAnchor fixation level and thus protect the EVAR from collapse.

Treatment of arteriovenous access pseudoaneurysms using ultrasound guided balloon assisted thrombin injection: Two cases and systematic review of the literature.

BACKGROUND: Arteriovenous fistula pseudoaneurysm (AVF-PSA) is a common complication, usually caused during dialysis cannulation, which traditionally has been treated with open and less frequently endovascular techniques. Thrombin injection, although established in the treatment of arterial pseudoaneurysms, has barely been used in the treatment of AVF-PSA, due to concerns for AVF thrombosis or proximal embolization. METHODS: A systematic review was performed according to the PRISMA 2020 guidelines. PubMed and Cochrane Central databases were reviewed and all clinical reports on AVF-PSA balloon assisted percutaneous thrombin injection through July 2022 were included. The electronic search yielded five case reports. Due to between-study differences and small sample size, the findings were summarized from each report, but the results were not pooled. Additionally, we present our own experience on two patients with AVF-PSA that were treated with balloon assisted percutaneous thrombin injection. RESULTS: A total of five case reports (no of patients: 7, including ours) were included for review. Most of the patients were male (n = 6) and the mean age was 65.9 years. The average size of the PSA was 1.6 cm. In all cases a balloon was inflated to prevent thrombin and thrombotic material intrusion into the fistula lumen, prior to thrombin injection. In one patient n-butyl cyanoacrylate and Lipiodol were used, due to thrombin non availability. Recurrence was reported in only one patient, and average follow-up is 16 months. CONCLUSIONS: Thrombin injection with concomitant balloon inflation seems to be a safe and effective treatment for arteriovenous fistula pseudoaneurysms. Future studies should be aimed at evaluating the long-term outcomes of such minimally invasive techniques.

Low-molecular-weight heparin compared with unfractionated heparin in critically ill COVID-19 patients.

BACKGROUND: Thrombosis in COVID-19 worsens mortality. In our study, we sought to investigate how the dose and type of anticoagulation (AC) can influence patient outcomes. METHODS: This is a single-center retrospective analysis of critically ill intubated patients with COVID-19, comparing low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) at therapeutic and prophylactic doses. Of 218 patients, 135 received LMWH (70 prophylactic, 65 therapeutic) and 83 UFH (11 prophylactic, 72 therapeutic). The primary outcome was mortality. Secondary outcomes were thromboembolic complications confirmed on imaging and major bleeding complications. Cox proportional-hazards regression models were used to determine whether the type and dose of AC were independent predictors of survival. We performed Kaplan-Meier survival analysis to compare the cumulative survivals. RESULTS: Overall, therapeutic AC, with either LMWH (65% vs 79%, P = .09) or UFH (32% vs 46%, P = .73), conveyed no survival benefit over prophylactic AC. UFH was associated with a higher mortality rate than LMWH (66% vs 28%, P = .001), which was also evident in the multivariable analysis (LMWH vs UFH mortality, hazard ratio: 0.47, P = .001) and in the Kaplan-Meier survival analysis. Thrombotic and bleeding complications did not depend on the AC type (prophylactic LMWH vs UFH: thrombosis P = .49, bleeding P = .075; therapeutic LMWH vs UFH: thrombosis P = .5, bleeding P = .17). When comparing prophylactic with therapeutic AC, the rate of both thrombotic and bleeding complications was higher with the use of LMWH compared with UFH. In addition, transfusion requirements were significantly higher with both therapeutic LMWH and UFH. CONCLUSIONS: Among intubated critically ill COVID-19 intensive care unit patients, therapeutic AC, with either LMWH or UFH, conveyed no survival benefit over prophylactic AC. AC with LMWH was associated with higher cumulative survival compared with AC with UFH.

A Case of Phlegmasia Cerulea Dolens in a Patient With COVID-19, Effectively Ttreated With Fasciotomy and Mechanical Thrombectomy.

Coronavirus disease 2019 (COVID-19) has been widely reported to be associated with increased risk of Venous Thromboembolism, both deep vein thrombosis (DVT) and pulmonary embolism. A rare and extreme manifestation of DVT is Phlegmasia cerulea dolens, characterized by poor tissue perfusion due to marked limb swelling which can progress to limb and life-threatening venous gangrene. We report the case of a 53-year-old man with severe SARS-CoV2 pneumonia who developed acute iliofemoral DVT leading to acute limb ischemia due to Phlegmasia cerulea dolens. The patient underwent successful emergent fasciotomy and mechanical thrombectomy with removal of extensive thrombus burden and restoration of normal venous circulation. Our case highlights the importance of clinical vigilance and early implementation of therapeutic interventions to avoid adverse outcomes in patients who develop SARS-CoV2 induced Venous Thromboembolism complications.

Aggressive Anticoagulation May Decrease Mortality in Obese Critically Ill COVID-19 Patients.

BACKGROUND: Obesity is a widely accepted risk factor for the development of severe COVID-19. We sought to determine the survival benefit of early initiation of aggressive anticoagulation in obese critically ill COVID-19 patients. METHODS: We retrospectively reviewed 237 intubated patients at a single academic accredited bariatric center and stratified them based on their BMI into 2 groups, obese (BMI > 30) and non-obese (BMI ≤ 30). We used chi-square tests to compare categorical variables such as age and sex, and two-sample t-tests or Mann Whitney U-tests for continuous variables, including important laboratory values. Cox proportional-hazards regression models were utilized to determine whether obesity was an independent predictor of survival and multivariable analysis was performed to compare risk factors that were deemed significant in the univariable analysis. Survival with respect to BMI and its association with level of anticoagulation in the obese cohort was evaluated using Kaplan-Meier models. RESULTS: The overall mortality in the obese and non-obese groups was similar at 47% and 44%, respectively (p = 0.65). Further analysis based on the level of AC showed that obese patients placed on early aggressive AC protocol had improved survival compared to obese patients who did not receive protocol based aggressive AC (ON-aggressive AC protocol 26% versus OFF-aggressive AC protocol 61%, p = 0.0004). CONCLUSIONS: The implementation of early aggressive anticoagulation may balance the negative effects of obesity on the overall mortality in critically ill COVID-19 patients.

D-Dimer-Driven Anticoagulation Reduces Mortality in Intubated COVID-19 Patients: A Cohort Study With a Propensity-Matched Analysis.

Objective: Examine the possible beneficial effects of early, D-dimer driven anticoagulation in preventing thrombotic complications and improving the overall outcomes of COVID-19 intubated patients. Methods: To address COVID-19 hypercoagulability, we developed a clinical protocol to escalate anticoagulation based on serum D-dimer levels. We retrospectively reviewed all our first 240 intubated patients with COVID-19. Of the 240, 195 were stratified into patients treated based on this protocol (ON-protocol, n = 91) and the control group, patients who received standard thromboprophylaxis (OFF-protocol, n = 104). All patients were admitted to the Stony Brook University Hospital intensive care units (ICUs) between February 7th, 2020 and May 17, 2020 and were otherwise treated in the same manner for all aspects of COVID-19 disease. Results: We found that the overall mortality was significantly lower ON-protocol compared to OFF-protocol (27.47 vs. 58.66%, P < 0.001). Average maximum D-dimer levels were significantly lower in the ON-protocol group (7,553 vs. 12,343 ng/mL), as was serum creatinine (2.2 vs. 2.8 mg/dL). Patients with poorly controlled D-dimer levels had higher rates of kidney dysfunction and mortality. Transfusion requirements and serious bleeding events were similar between groups. To address any possible between-group differences, we performed a propensity-matched analysis of 124 of the subjects (62 matched pairs, ON-protocol and OFF-protocol), which showed similar findings (31 vs. 57% overall mortality in the ON-protocol and OFF-protocol group, respectively). Conclusions: D-dimer-driven anticoagulation appears to be safe in patients with COVID-19 infection and is associated with improved survival. What This Paper Adds: It has been shown that hypercoagulability in patients with severe COVID-19 infection leads to thromboembolic complications and organ dysfunction. Anticoagulation has been variably administered to these patients, but it is unknown whether routine or escalated thromboprophylaxis provides a survival benefit. Our data shows that escalated D-dimer driven anticoagulation is associated with improved organ function and overall survival in intubated COVID-19 ICU patients at our institution. Importantly, we found that timely escalation of this anticoagulation is critical in preventing organ dysfunction and mortality in patients with severe COVID-19 infection.

Acute superior mesenteric artery thrombosis seven days after discharge for novel coronavirus pneumonia.

Since the emergence of novel coronavirus pneumonia (NCP), a number of reports have pointed out an increased coagulation activity in these patients mostly during acute phase of the disease. We are reporting a case of acute superior mesenteric thrombosis in a 55-year-old man with NCP 1 week after hospital discharge. He returned to the emergency department 7 days later with severe acute abdominal pain and found to have superior mesenteric artery thrombosis. He subsequently underwent emergent exploratory laparotomy, superior mesenteric artery thrombectomy, and bowel resection. Acute arterial thrombosis may occur in the posthospitalization period in patients with NCP.

Safety and effectiveness of the TREO stent graft for the endovascular treatment of abdominal aortic aneurysms.

OBJECTIVE: The short- and mid-term outcomes of endovascular aortic aneurysm repair have made it a standard treatment of abdominal aortic aneurysms. However, newer generation devices have yet to demonstrate improved long-term rates for complications, reinterventions, and survival. The TREO stent graft is a latest generation device and was evaluated for approval in the United States. METHODS: In a multicenter, nonrandomized, investigational device exemption clinical trial, we assessed the safety and effectiveness of the TREO device, with core laboratory assessment of the imaging studies and an independent adjudication of safety. The primary effectiveness endpoint was successful aneurysm treatment at 1 year. The primary safety endpoint was the incidence of major adverse events (MAE) at 30 days. RESULTS: A total of 150 patients (132 men; 88.0%) with infrarenal abdominal aortic (87.3%) or aortoiliac (12.7%) aneurysms were enrolled. The data were normally distributed. The mean age was 71.7 ± 7.4 years. The MAE incidence at 30 days was 0.7%. One subject experienced two MAE: myocardial infarction and procedural blood loss of 1000 mL. The proportion of successful aneurysm treatment at 1 year was 93.1%. Longer term follow-up continues, with no aneurysm-related mortality at the latest follow-up. At 3 years, the cumulative all-cause mortality and incidence of type I and type III endoleaks was 10.7% (n = 16), 2.7% (n = 4), and 0% (n = 0), respectively. In addition, aneurysm sac shrinkage >5 mm at 3 years had occurred in 54.3% of patients, and 9.3% had required a secondary intervention (n = 14). CONCLUSIONS: The safety and effectiveness of endovascular repair of abdominal aneurysms with TREO were demonstrated, with 93.1% successful aneurysm treatment at 1 year and aneurysm sac shrinkage >5 mm at 3 years in 54.3% of patients. Long-term follow-up continues to determine whether these favorable outcomes will be sustained.

Tracheobronchial Slough, a Potential Pathology in Endotracheal Tube Obstruction in Patients With Coronavirus Disease 2019 (COVID-19) in the Intensive Care Setting.

BACKGROUND: A novel coronavirus (COVID-19) erupted in the latter part of 2019. The virus, SARS-CoV-2 can cause a range of symptoms ranging from mild through fulminant respiratory failure. Approximately 25% of hospitalized patients require admission to the intensive care unit, with the majority of those requiring mechanical ventilation. High density consolidations in the bronchial tree and in the pulmonary parenchyma have been described in the advanced phase of the disease. We noted a subset of patients who had a sudden, significant increase in peak airway, plateau and peak inspiratory pressures. Partial or complete ETT occlusion was noted to be the culprit in the majority of these patients. METHODS: With institutional IRB approval, we examined a subset of our mechanically ventilated COVID-19 patients. All of the patients were admitted to one of our COVID-19 ICUs. Each was staffed by a board certified intensivist. During multidisciplinary rounds, all arterial blood gas (ABG) results, ventilator settings and ventilator measurements are discussed and addressed. ARDSNet Protocols are employed. In patients with confirmed acute occlusion of the endotracheal tube (ETT), acute elevation in peak airway and peak inspiratory pressures are noted in conjunction with desaturation. Data was collected retrospectively and demographics, ventilatory settings and ABG results were recorded. RESULTS: Our team has observed impeded ventilation in intubated patients who are several days into the critical course. Pathologic evaluation of the removed endotracheal tube contents from one of our patients demonstrated a specimen consistent with sloughed tracheobronchial tissues and inflammatory cells in a background of dense mucin. Of 110 patients admitted to our adult COVID-19 ICUs, 28 patients required urgent exchange of their ETT. CONCLUSION: Caregivers need to be aware of this pathological finding, recognize, and to treat this aspect of the COVID-19 critical illness course, which is becoming more prevalent.

Endovascular repair of infected carotid pseudoaneurysm: A case report.

BACKGROUND: Pseudoaneurysm (PA) of the carotid artery is a rare but life-threatening complication following carotid endarterectomy (CEA). Management of carotid PAs is challenging due to the increased risk of stroke and nerve injury in an infected and re-operative field. Open surgery has been the mainstay for this complicated pathology however some patients have characteristics which make an endovascular approach more advantageous. Yet endovascular intervention for infected fields is scrutinized and used as a last option. HISTORY AND TREATMENT PLAN: 72 year old female with history of basilar artery aneurysm embolization and right internal carotid artery occlusion presented with a left carotid pseudoaneurysm after a CEA 6 months prior. She presented with 2 days of increasing left neck swelling, erythema, and a small ulcerated area with bloody discharge from incision site. A Computed Tomagraphy scan (CTA) showed hematoma surrounding the left ICA concerning for PA. Wound cultures were obtained which grew coagulase (-) staphylococcus. We elected to perform an endovascular procedure to temporize the bleeding by placing a stent graft (7 mm × 7.5 cm Gore Viabahn) across the left ICA. She remains asymptomatic with no recurrent symptoms 6 months postoperatively. CONCLUSION: Our experience in this patient indicates that endovascular stenting could be feasible and potentially effective intervention for infection-associated post-CEA PA in patients with an excessively high risk for stroke and nerve injury. We suggest each patient should be evaluated individually and all pertinent characteristics should be considered to make the best decision.

Endovascular Treatment of Persistent Sciatic Artery Aneurysms With Primary Stenting: A Systematic Review of the Literature.

Persistent sciatic artery (PSA) is an embryologic remnant of the internal iliac artery, and when is present, it undergoes aneurysmal degeneration in up to 60% of the cases. Endovascular repair is an increasingly utilized treatment strategy for PSA aneurysms (PSAAs). The objective was to demonstrate the safety and efficacy of the endovascular repair in patients with PSAA and to identify potential risk factors for loss of patency or limb loss. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and eligible studies were identified through search of the PubMed, Scopus, and Cochrane Central databases. Fifteen case reports, comprising 15 patients overall, were included. The median age of the patients was 68 years old (mean age 66 ± 13.4 years) with half of the reported patients being women. Most patients presented with progressive limb claudication, complaining about an enlarging palpable pulsatile buttock mass. The onset of symptoms was sudden in 78% of the reported cases. Additionally, the distal pulses on PSAA side were diminished or absent in 91% of the patients. Acute limb ischemia was the primary diagnosis in 75% of the cases. All patients underwent endovascular repair of the PSAA with a covered stent. Procedural outcomes were favorable in all patients demonstrating no symptoms recurrence, aneurysmal regression, or total obliteration evaluated by angiographic studies (computed tomography angiography [CTA] and angiogram). Periprocedural imaging evaluation was determined either with CTA or duplex ultrasound (DUS). Periprocedural complications included only 1 endoleak with distal dissection. This endoleak was identified after stent deployment and dissection distal to the aneurysm. Mean follow-up (with CTA and/or DUS) was 22 months, with all patients being asymptomatic with no recurrence of symptom. The endovascular treatment of PSAA with covered stent is safe and effective. Persistent sciatic artery aneurysms is associated with high procedural success, low periprocedural compilations, and favorable mid-term follow-up.

Endovascular Repair of the Ascending Aorta for an Anastomotic Saphenous Vein Graft Aneurysm.

The ascending aorta is the final segment of the aorta to be explored with endovascular stent grafts. With a patient population of increasingly advanced age and disease, there are situations where traditional open repair for ascending aneurysms or dissections may be prohibitive. However, the ascending aorta has multiple hostile characteristics that make endovascular treatment challenging. There is also a lack of approved specialized devices in the United States for this aortic territory. We demonstrate the feasibility of adapting an abdominal aortic graft to the ascending aorta for the treatment of a saphenous vein graft aneurysm with a discussion of the technical considerations for the operation.

Endovascular Thoracic Aortic Repair for Catheter Associated Aortic Injury During Thoracostomy Tube Placement.

BACKGROUND: Aortic injuries during non-aortic related procedures are rare but potentially catastrophic. Endovascular aortic repair has been described as a viable option in similar circumstances. However, most reports involve aortic injury from orthopaedic hardware after spine surgery or trocar injury during abdominal surgery. REPORT: This is a report of a thoracic aortic injury during thoracostomy tube placement and summary of the management paradigm. The patient was treated with a thoracic stent graft and was seen at four-month follow up, with imaging showing the endograft in stable position. CONCLUSION: Endovascular stenting can increase the treatment scope for management of emergent thoracic aortic pathology.

Intimomedial mucoid degeneration of the peripheral arteries.

Intimomedial mucoid degeneration, a rare vascular disorder characterized by mucinous deposition in the intima and media layers, causes aneurysmal degeneration of the vessel wall in young patients. Because of the potential for involvement of multiple vessels, these patients may require full body imaging and long-term follow-up. We describe three patients with intimomedial mucoid degeneration and variable clinical presentations. One patient presented emergently with a spontaneously ruptured nonaneurysmal subclavian artery; one patient presented with a known posterior tibial artery aneurysm and new onset of focal pain and paresthesias over the aneurysm; and one patient presented with a self-discovered dorsalis pedis artery aneurysm.