Cryopreserved Human Allografts for the Reconstruction of Aortic and Peripheral Prosthetic Graft Infection

Ten-year experience with cryopreserved vascular allografts in the Croatian Cardiovascular Tissue Bank

The Croatian Cardiovascular Tissue Bank (CTB) was established in June 2011. Activities managed by CTB are processing of heart valves and blood vessels, as well as quality control, storage, medical release and distribution of allografts. The aim of this report is to present CTB's vascular tissue activities and retrospectively evaluate the outcomes of their use in the University Hospital Centre Zagreb. Between June 2011 and July 2021, 90 vascular allografts (VAs) from 55 donors after brain death were referred to CTB. Only 54% of VAs met the tissue quality requirements while 46% of tissues were discarded. The most frequent reasons for discard were unacceptable morphology and initial microbiological contamination. Altogether 42 VAs were released for transplantation and 37 of them were used in 27 surgical procedures. The most common indication for surgery was prosthetic graft or stent infection. According to the anatomic position of vascular reconstruction, patients were divided in the aortic and peripheral reconstruction group. A total of 23 patients were treated. In the aortic reconstruction group 58% of patients did not experience any graft-related complications. In the group of patients who underwent peripheral reconstruction significant incidence of reinfection was observed highlighting it as a major graft-related complication. Despite the small patient groups and limited duration of follow-up, presented clinical outcomes provide valuable information on the efficacy of vascular allografts. Additional clinical results collected on a larger patient groups and comparison to other reconstructive treatment options are necessary.

Multislice Computed Tomography Angiography Imaging Diagnosis of Lower Extremity Arteriosclerosis in Patients with Hypertension and Its Correlation with the Level of High-Sensitivity C-Reactive Protein

The aim of this study was to investigate the relationship between multislice computed tomography (CT) angiography (MSCTA) imaging and high-sensitivity C-reactive protein (hs-CRP) in patients with hypertension and lower extremity arteriosclerosis. 68 hypertensive patients with lower extremity arteriosclerosis were selected as the observation group, and 68 healthy volunteers were selected as the control group to compare the differences in hs-CRP. According to the degree of stenosis, the patients were further divided into five grades: no obvious stenosis, mild stenosis, moderate stenosis, severe stenosis, and occlusion. The correlation between the degree of stenosis and the content of hs-CRP was compared. The changes of hs-CRP content before and after treatment were compared, and the difference of images before and after surgical treatment and the difference of hs-CRP expression in patients with occlusion were compared. Compared with the control group, the content of hs-CRP in the observation group was significantly higher ( $P<0.05$ ), and the degree of stenosis was positively correlated with the content of hs-CRP. After two weeks of treatment, the hs-CRP levels of patients with severe stenosis and occlusion were significantly lower than those before treatment ( $P<0.01$ ). The level of hs-CRP in patients with occlusion after arterial stent intervention was significantly lower than before, and the images also showed that the blood vessels were significantly expanded. The degree of stenosis in patients with lower extremity arteriosclerosis diagnosed by MSCTA imaging was closely related to the expression of hs-CRP in the patient, and a sustained high concentration of hs-CRP corresponded to a more severe degree of vascular occlusion. In conclusion, the hs-CRP can be used as one of the factors to predict and evaluate the occurrence of cardiovascular and cerebrovascular diseases.

Extraanatomic bypass grafting in a patient with an infected femoral defect caused by a rollover accident: a case report

A 59-year-old male patient presented to the emergency department after a tractor rollover accident. His Injury Severity Score was 41 points. He had multiple pelvic bone fractures and a left common femoral artery injury with soft tissue loss. The injured arteries with skin defect were initially managed with endarterectomy and primary repair. However, the sepsis secondary to the infection from a skin defect became uncontrolled. The infected wound developed massive hemorrhage from the repaired arteries. Supportive measures were initiated to achieve hemostasis but unsuccessful. We performed an anastomosis with a prosthetic graft from the common iliac artery to the femoral artery above the knee, avoiding the wound through the lateral side of the anterior superior iliac spine. After revascularization, the patient recovered uneventfully. An extraanatomic graft reconstruction should be considered early when the autologous vein is unsuitable.

Outcomes of biosynthetic vascular graft for infrainguinal femoro-popliteal and femoro-distal revascularization

BACKGROUND

The aim of this study was to retrospectively analyze early and late outcomes of infrainguinal revascularization performed with the Omniflow-II^® (LeMaitre Vascular, Inc., Burlington, MA, USA) biosynthetic vascular graft (BVG) for complex femoro-popliteal obstructive disease.

METHODS

Over a 10-year period, this BVG was used in 110 patients who underwent infrainguinal femoro-popliteal or femoro-distal bypass. Early (intraoperative and <30 days) results were analyzed in terms of death, thrombosis, amputations and reinterventions. Follow-up results were analyzed in terms of primary and secondary graft patency, and amputation-free survival.

RESULTS

We performed 87 (79.1%) above-the-knee bypass, 20 (18.2%) below-the-knee bypass, and 3 (2.7%) tibial artery bypass. In-hospital mortality was not observed. Mean follow-up was 66±37 months (range, 3-150). Estimated primary patency rate at 1, 2 and 5-years of follow-up was 77%±4 (95%CI: 68-84), 73%±5 (95%CI: 63.5-83), and 59%±6 (95%CI: 47-70.5) respectively. Predictors of primary patency loss were the presence of critical limb ischemia (P=0.048; HR: 2.1; 95%CI: 1.01-4.28), and the necessity of below-the-knee bypass (P=0.012; HR: 2.4; 95%CI: 1.22-4.75). Aneurysmal degeneration of the BVG was detected in 4 (3.6%) patients, an infected BVG occurred in 3 (2.7%) patients. The amputation-free survival was 96%±2 (95%CI: 91-99), 93%±3 (95%CI: 86-96), and 76%±5 (95%CI: 66-84) at 1, 2 and 5-years respectively.

CONCLUSIONS

In our experience, Omniflow-II^® is a valid first-line alternative for infrainguinal revascularization when the ipsilateral autologous saphenous vein is not available. Aneurysmal degeneration was lower than previously reported with alternative BVGs, and the incidence of BVG infection was acceptably low.

Novel prefabricated bovine pericardial grafts as alternate conduit for septic aortoiliac reconstruction

OBJECTIVE

Infection of prosthetic aortic grafts represents a serious complication with high morbidity and mortality. Replacement with autologous material is recommended; however, in its absence, biological material should be favored. In the present retrospective cohort study, we evaluated the short- and midterm results with the use of commercially available prefabricated bovine pericardium grafts (BPGs) used for the management of aortic graft infection or aortic reconstructive surgery in the presence of systemic infection.

METHODS

We performed a retrospective analysis of patients in whom BPGs had been used for aortic reconstruction at two vascular centers. Prefabricated vascular pericardium grafts were preferred over other biological reconstruction techniques for selected cases. Comorbidities, procedure-related details, perioperative morbidity, clinical outcomes, and mortality were analyzed.

RESULTS

From 2014 to 2019, 21 patients had received BPGs at two Austrian vascular centers. Their median age was 63 years (interquartile range [IQR], 55-71 years), the patients were predominantly male (76%), and the median body mass index was 25.3 kg/m² (IQR, 21.7-27.3 kg/m²). The major comorbidities included arterial hypertension, peripheral artery disease, smoking, and chronic pulmonary disease. The indications for surgery were vascular graft or endograft infection in 62% and aortic reconstruction in the presence of systemic infection in 38%. Three patients (14%) had aortoenteric fistulas. Surgery was technically successful in all cases. The median follow-up was 21.6 months (IQR, 6.0-34.6 months). The 30-day mortality was 9.5%. The 1- and 2-year overall survival was 84% and 75%, respectively. Of the 21 patients, 89% had remained free of recurrent infection. One of the two reinfections had resolved after treatment of the underlying focus. At 2 years, the primary and assisted primary patency rates were 86% and 94%, respectively. No limbs were lost during follow-up.

CONCLUSIONS

Prefabricated BPGs represent a promising alternative for the management of aortic graft infections and aortoiliac reconstruction in the presence of systemic infection.

Infrarenal Aortic Endograft Infection: A Single-Center Experience

PURPOSE:

Endograft infection is an infrequent but one of the most serious and challenging complications after endovascular aortic repair. The aim of this study was to assess the management of this complication in a tertiary center.

CASE SERIES:

A retrospective analysis of a prospective database was performed including all patients who underwent elective endovascular abdominal aortic repair (EVAR) from 2003 to 2016 in a tertiary center. Seven cases of endograft infection were identified during the follow-up period from a total of 473 (1.48%) EVAR. Most frequent symptoms at presentation were fever (71.4%) and lumbar pain (57.1%). One case developed an early infection, while 6 cases were diagnosed as late infections. Mean time from endograft placement to symptom presentation was 28.3 months (2-91.5 months). Gram-positive cocci were the microorganisms most commonly isolated in blood cultures (66%). Two cases were managed with endograft removal and aortic reconstruction with a cryopreserved allograft, 2 cases with surgical drainage, and 2 cases exclusively with antibiotic therapy. In 1 case, the diagnosis was performed postoperatively based on intraoperative findings associated with positive graft cultures; and graft explantation was performed with "in situ" reconstruction using a Dacron graft. Perioperative mortality was 42.9%. One-year mortality was 57.1%. Mean follow-up was 21.5 months.

CONCLUSION:

Endograft explantation is the gold standard of treatment; however, given the overall high morbi-mortality rates of this pathology, a tailored approach should always be offered depending on the patient's overall condition. Conservative management can be an acceptable option in those patients with short life expectancy and high surgical risk.