Staged Endovascular and Surgical Management of a Mycotic Pseudoaneurysm After Pancreas Transplant.

Mycotic pseudoaneurysms are a rare, life-threatening complication after pancreas transplant. There have been limited reports of endovascular treatment of mycotic pseudoaneurysms in pancreas transplant recipients. Herein, we report on a case of a mycotic pseudoaneurysm from Pseudomonas aeruginosa after pancreas transplant. A 53-year-old male recipient underwent an uneventful simultaneous pancreas and kidney transplant. He was readmitted 48 days posttransplant with fevers and rigors. Pan-cultures were performed and broad-spectrum antibiotics were initiated. Imaging studies demonstrated a large mycotic pseudoaneurysm arising from the right common iliac artery adjacent to the arterial Y-graft anastomosis of the transplant pancreas. Endovascular stent placement was used to exclude the pseudoaneurysm prior to transplant pancreatectomy. During pancreatectomy, the lateral wall of the common iliac artery was found to be necrotic with significant exposure of the endovascular stent. After ligation and excision of the common iliac artery, a femorofemoral bypass was performed to revascularize the lower extremity. This case report highlights the advantage of a staged endovascular and surgical management strategy for complex mycotic pseudoaneurysms after pancreas transplant.

Response to clopidogrel in patients undergoing lower extremity revascularization.

OBJECTIVES: Clopidogrel is effective at decreasing cardiovascular events in patients with peripheral artery disease (PAD); however, its effect on limb outcomes are less known. This study investigated the variability in response to clopidogrel and its relationship with clinical limb outcomes. METHODS: Three hundred subjects were enrolled in the Platelet Activity and Cardiovascular Events (PACE) study prior to lower extremity revascularization, of whom 104 were on clopidogrel. Light transmission platelet aggregation was measured in response to ADP 2 µm immediately prior to revascularization. Patients were followed longitudinally for a median follow-up of 18 months. The primary endpoint was major adverse limb events (MALE) defined by major amputation or reoperation of the affected limb. Patients were stratified into groups according to percent ADP-induced aggregation. Poor response to clopidogrel was defined by >50% aggregation. RESULTS: Overall, the median age was 70 (63, 76) and 35.6% were female. Twenty-nine (27.9%) patients experienced MALE during their follow-up. Median aggregation to ADP 2 µ m was 22.5% (Q1-Q3: 10%, 50%) and 27 subjects (26%) were clopidogrel poor responders. Baseline aggregation was higher in subjects who went on to develop a MALE than those without MALE (43% vs 20%, p = .017). Subjects with aggregation > median (22.5%) were more likely to experience MALE than aggregation < median (38.5% vs 17.3%, p = .029). After multivariable adjustment for age, sex, race/ethnicity, BMI, diabetes, coronary artery disease, and aspirin use, aggregation > median was associated with MALE (adjusted HR [aHR] 2.67, 95% CI 1.18-6.01, p = .018). When stratified by established cut-offs for responsiveness to clopidogrel (50% aggregation), poor responders were more likely to experience MALE than normal responders (44.4% vs 22.1%, aHR 2.18, 95% CI 1.00-4.78, p = .051). CONCLUSIONS: Among patients undergoing lower extremity revascularization on clopidogrel, higher baseline percent aggregation is associated with increased risk for major adverse limb events.

Anticoagulation Therapy is Associated with Increased Access-related Wound Infections after Hemodialysis Access Creation.

BACKGROUND: The effect of anticoagulation therapy (AC) on hemodialysis access patency and related complications is not well defined. Patients on long-term or chronic AC due to their underlying comorbid conditions may be particularly susceptible to access-related bleeding and complications from repetitive cannulation. Our goal is to assess the effect of anticoagulation therapy on outcomes after access creation. METHODS: The Vascular Quality Initiative (VQI) database was queried for patients undergoing arteriovenous fistula (AVF) or graft (AVG) placement, from 2011 to 2019. Only patients with data on post-procedural AC status were included. Anticoagulation use was defined as patients on warfarin, dabigatran, or rivaroxaban after access creation at postoperative follow up. Demographic and procedural details were analyzed. Wound infection and patency rates at six months were assessed. Binomial logistic regression analysis was performed to assess the association of anticoagulation use with these outcomes. RESULTS: A total of 27,757 patients underwent access creation, with the majority undergoing AVF creation (78.8%). The average age was 61.4 years and 55.3% were male. 12.9% of patients were on postoperative AC. The wound infection rate was 2.3- 3.8% in the no AC and AC cohorts, respectively (P < 0.001). At six months follow-up, patency was 85.7- 84.3% in the no AC and AC cohorts, respectively (P = 0.044). Expectedly, grafts had lower patency rates compared to AVF; those within the no AC cohort had a patency of 83.0% compared to 81.2 % in those on AC (P = 0.106). On multivariable analysis, anticoagulation use was associated with a higher risk of wound infections (odds ratio [OR] 1.513, 95% confidence interval [CI] 1.160-1.973, P = 0.002). AC use did not significantly affect access patency. CONCLUSION: Anticoagulation therapy was associated with a higher rate of wound infections but did not affect short-term access patency within six-months. These patients warrant close surveillance of their access for signs of infection. Furthermore, long-term implications of anticoagulation needs further evaluation.

Arterial thromboembolism associated with COVID-19 and elevated D-dimer levels.

The novel coronavirus 2019 (SARS-CoV-2) was first identified in January 2020 and has since evolved into a pandemic affecting >200 countries. The severity of presentation is variable and carries a mortality between 1% and 3%. We continue to learn about the virus and the resulting acute respiratory illness and hypercoagulability; however, much remains unknown. In our early experience in a high-volume center, we report a series of four cases of acute peripheral artery ischemia in patients with COVID-19 in the setting of elevated D-dimer levels.

Presentation and Management of Arterial Thromboembolisms during Active Inflammatory Bowel Disease: Case Series and Literature Review.

BACKGROUND: Active inflammatory bowel disease (IBD) is associated with considerable risk for thromboembolism; however, arterial thromboembolism is rare and associated with considerable morbidity and mortality. Their management requires careful coordination between multiple providers, and as a consequence, much of the published literature is limited to case reports published across specialties. METHODS: We examined our recent institutional experience with aortoiliac, mesenteric, and peripheral arterial thromboembolisms in patients with either Crohn's disease or ulcerative colitis. To supplement our experience, a comprehensive literature review was performed using MEDLINE and EMBASE databases from 1966 to 2019. Patient demographics, flare/thromboembolism management, and outcomes were abstracted from the selected articles and our case series. RESULTS: Fifty-two patients with IBD, who developed an arterial thromboembolism, were identified (49 from published literature and 3 from our institution). More than 82% of patients presented during an active IBD flare. Surgical intervention was attempted in 77% of patients, which included open thromboembolectomy, catheter-directed thrombolysis, or bowel resection. Thromboembolism resolution was achieved in 76% of patients with comparable outcomes with either catheter-directed thrombolysis or open thrombectomy (83.3% vs. 68.2%). Nearly one-third of patients underwent small bowel resection or colectomy. In 2 patients, thromboembolism resolution was achieved only after total abdominal colectomy for severe pancolitis. Multiple thromboembolectomies were associated with higher risk for amputation. Overall mortality was 11.5% but was greatest for occlusive aortoiliac and mesenteric thromboembolism (14.3% and 57%, respectively). All survivors of occlusive superior mesenteric artery thromboembolism suffered short gut syndrome requiring small bowel transplant. CONCLUSIONS: Patients with IBD, who develop an arterial thromboembolism, can expect overall poor outcomes. Catheter-directed thrombolysis achieved comparable outcomes with open thromboembolectomy without undue bleeding risk. Total abdominal colectomy for moderate-to-severe pancolitis is an emerging strategy in the management of refractory arterial thromboembolism. Successful surgical management may include open thromboembolectomy, catheter-directed thrombolysis, and bowel resection when indicated.

Occluded Superficial Femoral and Popliteal Artery Stents Can Have a Negative Impact on Bypass Target.

PURPOSE: To identify whether occluded femoropopliteal stents influence previously available lower extremity bypass (LEB) targets. METHODS: Among 621 consecutive patients who had undergone stenting of a superficial femoral artery or popliteal artery lesion from January 2009 to December 2013, 30 patients (mean age 69.9±10.2 years; 16 women) were found to have occluded stents. Angiograms before stent placement were analyzed to determine what would have been the optimal distal bypass site, which was compared with the angiogram following stent occlusion. RESULTS: Seven (22%) limbs lost the bypass target. In one limb, the target changed from above-knee to below-knee popliteal, in 2 limbs from above-knee popliteal to tibial, and in 4 limbs from below-knee popliteal to tibial artery. Eleven (34%) limbs required LEB during follow-up. Chronic obstructive pulmonary disease (p=0.007), chronic renal insufficiency (p=0.026), a popliteal artery stent (p=0.001), and the below-knee popliteal artery as an optimal bypass target (p=0.026) were associated with loss of bypass target following stent occlusion. CONCLUSION: Superficial femoral artery and popliteal artery stent occlusion can affect target vessels in patients who may require subsequent LEB. This should be considered when performing stenting.

Acute Paget-Schroetter syndrome: does the first rib routinely need to be removed after thrombolysis?

BACKGROUND: Most clinicians feel that treatment for patients with acute primary axillosubclavian vein thrombosis ("effort thrombosis") is catheter-directed thrombolysis followed by thoracic outlet decompression. Several investigators feel that first rib resection (FRR) is not indicated in every case. No randomized data exist to answer this question. METHODS: A MEDLINE search was done using the terms "Paget-Schroetter syndrome," "upper extremity DVT," "first rib resection," "effort thrombosis," and "primary upper extremity thrombosis," with thrombolysis used as an "AND" term. We also specifically explored references cited to support either side of this argument in the past. Analysis was limited to patients aged 18 years or older with symptoms of 14-day duration or less undergoing thrombolysis for primary axillosubclavian vein thrombosis. Those studies that did not report follow-up, duplicate series from the same institution, and those in which patients were stented were excluded. Results were analyzed on an intent-to-treat basis, with groups assigned according to each authors' prospectively described algorithm. RESULTS: Twelve series were included. Patients were divided into 3 groups according to treatment after thrombolysis: FRR (448 patients), FRR plus endovenous balloon venoplasty (FRR + PLASTY; 68 patients), and those with no further intervention after thrombolysis (rib not removed; 168 patients). Symptom relief at last follow-up was significantly more likely in the FRR (95%) and FRR + PLASTY (93%) groups than in the rib not removed (54%) group (both <0.0001) as was patency (98%, 86%, and 48%, respectively; both <0.0001 vs. rib not removed). More than 40% of patients in the rib not removed group eventually required rib resection for recurrent symptoms. No differences in symptom-free rates were seen when comparing FRR with FRR + PLASTY. CONCLUSIONS: In patients with acute effort thrombosis who undergo thrombolysis, permanent symptom relief and long-term patency are more likely to be achieved in patients who undergo FRR with or without endovenous balloon venoplasty than those whose rib is left intact.

Outcomes of open surgical repair for chronic type B aortic dissections.

OBJECTIVE: Open surgical repair (OSR) for chronic type B aortic dissection (CTBAD) has an associated morbidity and mortality. The role of thoracic endovascular aortic repair (TEVAR) in CTBAD has not been determined. We analyzed our contemporary experience of CTBAD undergoing OSR to identify high-risk patients who may be considered for TEVAR. METHODS: From 1999 to 2010, 221 patients had repair of descending thoracic and thoracoabdominal aortic aneurysms, including 86 patients with CTBADs. We analyzed this cohort for mortality, complications, length of stay, and reinterventions. RESULTS: OSR was performed in 25 (29%) and 61 (71%) patients for descending thoracic and thoracoabdominal CTBAD, respectively. Median age was 57.0 years (interquartile range [IQR], 52.0-64.2 years), and median diameter was 6.0 cm (IQR, 5.0-6.9 cm). Fifty-nine patients (69%) were male. Eight (9%) were treated for rupture. Follow-up duration was 4.6 years (IQR, 2.8-6.9 years). Hospital mortality occurred in five patients (5.8%). Cardiopulmonary bypass was used in 83 patients (97%) and deep hypothermic arrest in 36 (42%). Two patients (2.3%) each developed paraplegia, stroke, and renal failure requiring permanent hemodialysis in the postoperative period. Length of stay was 13.5 days (IQR, 10.0-21.0 days). Univariate predictors of hospital death included redo operations and prolonged pump time (P < .05). Six patients (7%) had aortic-related reoperations at 4.3 years (IQR, 2.7-5.2 years): one for an ascending aortic aneurysm and five for descending aortic aneurysms. Overall survival at 1, 5, and 7 years was 92%, 83%, and 70%, respectively, and freedom from reoperation was 99%, 90%, and 86%, respectively. CONCLUSIONS: OSR of CTBAD is a durable option with low mortality. Patients requiring redo operations or anticipated prolonged pump time need further evaluation to determine whether conventional OSR or TEVAR, if feasible, is the optimal treatment option.

Demographic and laboratory data may predict positive temporal artery biopsy.

BACKGROUND: Temporal artery biopsy is performed in patients suspected of having giant cell arteritis. This study was conducted to evaluate clinical and laboratory criteria correlating with positive biopsy results in an effort to limit the number of negative biopsies performed. METHODS: A retrospective review was performed of patients who underwent temporal artery biopsy at two urban medical centers from 2002 to 2009. A multivariate analysis of patient demographics, clinically relevant signs and symptoms, laboratory data, and pathologic outcomes was performed. RESULTS: Temporal artery biopsy histologically confirmed giant cell arteritis in 24% of cases. The mean age of those with disease was 77.8 y and those without were 73.1 y; age was found to be statically significant (P = 0.0227); 76% were female and 24% were male; gender was not significant (P = 0.9594); 42% were Caucasian (39% had a positive temporal artery biopsy), 27% were Hispanic (17% positive), and 31% of the patients were African-American (3% positive); ethnicity was significant (P = 0.0005). The PPV of elevated ESR was 27%; sensitivity was 100%; specificity was 16%. A history of headache or visual disturbance was not predictive of a positive biopsy CONCLUSION: Fewer negative biopsy results may be achieved by screening patients with normal ESR or lower risk patients with other modalities.

Incidence and risk factors for the development of incisional hernia following elective laparoscopic versus open colon resections.

BACKGROUND: There are few studies that compare the incidence of incisional hernia following elective laparoscopic colon resection to open colectomy and determine the risk factors for its development. METHODS: Elective open and laparoscopic colon resections performed between February 2002 and May 2007 were reviewed. In the laparoscopic group, mesenteric transection was performed via intracorporeal division for left-sided colectomy and via extracorporeal technique for right-sided colectomy. The ileocolic anastomosis was performed by extracorporeal stapling for right colectomies and by intracorporeal for left colectomies. RESULTS: Two hundred eighteen patients (mean age 62 years, 52% male) underwent elective colon resection (50% open, 5% hand-assisted, and 45% laparoscopic). Six percent of the cases that started as laparoscopic were converted and are included in the open group. Mean follow-up was 26 months. The overall incisional hernia rate was 16% (open and minimally invasive group 17% vs 15%, P = .14). Hernia was not dependent on the type of resection, indication, or extraction site. Body mass index >36 kg/m(2), male gender, and surgical site infection were risk factors for hernia development. CONCLUSIONS: Laparoscopic colectomy does not reduce the development of incisional hernia.

Lipopolysaccharide O-antigen promotes persistent murine bacteremia.

Bacteremia is a common complication of pneumonia with Klebsiella pneumoniae. In the previous work, we have shown that the lipopolysaccharide (LPS) O-antigen in K. pneumoniae O1:K2 contributes to lethality during pneumonia in part by promoting bacteremia. In the current work, we studied an O-antigen-deficient K. pneumoniae strain to further evaluate this polysaccharide's role in bloodstream infection. Cultured macrophage and murine bacteremia models were studied. In vitro, O-antigen-deficient bacteria, compared with wild-type organisms, were stronger activators of the murine alveolar macrophage cell line MH-S as assessed by nuclear localization of RelA/p65 and by secretion of cytokines and chemokines. O-antigen-deficient Klebsiellae were also more susceptible to killing by murine neutrophils. In vivo, the absence of O-antigen allowed more rapid and complete clearance of bacteria from the bloodstream, liver, and spleen after intravenous injection in mice. Survival was also greater among animals infected with bacteria missing the O-antigen. Gene expression profiling (via reverse transcriptase-polymerase chain reaction of 84 inflammatory mediator complementary DNA) revealed that by 24 h postinfection, the livers and spleens of animals infected with O-antigen-deficient organisms had significantly downregulated cytokine and chemokine expression compared with wild-type infected animals. The O-antigen surface carbohydrate of O1:K2 serotype K. pneumoniae appears to contribute to bacterial virulence by lessening the activation of macrophages, conveying resistance to killing by neutrophils, and by promoting persistent infection in the blood, liver, and spleen after the onset of bacteremia.