Cryopreserved Allograft in the Management of Native and Prosthetic Aortic Infections

Infection of Vascular Prostheses: A Comprehensive Review

Vascular graft or endograft infection (VGEI) is a complex disease that complicates vascular-surgery and endovascular-surgery procedures and determines high morbidity and mortality. This review article provides the most updated general evidence on the pathogenesis, prevention, diagnosis, and treatment of VGEI. Several microorganisms are involved in VGEI development, but the most frequent one, responsible for over 75% of infections, is Staphylococcus aureus. Specific clinical, surgical, radiologic, and laboratory criteria are pivotal for the diagnosis of VGEI. Surgery and antimicrobial therapy are cornerstones in treatment for most patients with VGEI. For patients unfit for surgery, alternative treatment is available to improve the clinical course of VGEI.

[Prosthetic repair of the aorta with a cadaveric homograft for infection of bifurcated synthetic vascular prosthesis]

Infection of arterial vascular grafts is a rare but utterly severe complication in vascular surgery. Therapeutic policy in patients with graft infection has not been standardized, to be determined individually. One of the variants of surgical treatment is considered to be repeat aortic repair using a cadaveric graft. Presented in the article is a clinical case report concerning a 60-year-old male patient previously subjected to aortofemoral bifurcation bypass grafting with stage IV ischaemia of lower limbs according to the Pokrovsky-Fontaine classification. In the early postoperative period the events of critical ischaemia were not arrested. Due to the presence of a block of the femoropopliteal segment, as the second stage 3 days after the primary operation, the patient underwent autovenous femoropopliteal bypass grafting with a reversed autovein above the knee-joint fissure. The clinical course of critical ischaemia of the limb was relieved. During subsequent 8 months of follow up his state remained stable. Eight months after the primary operation he developed purulent discharge from the postoperative scar on the left femur. In the setting of the Purulent Surgery Department, the patient was emergently subjected to opening and drainage of the abscess of the postoperative scar. On the bottom of the wound there was a freely lying branch of a synthetic vascular prosthesis. Computed tomography revealed infection of the entire synthetic prosthesis and aneurysms of distal anastomoses. Given extremely high risk for the development of arrosive haemorrhage, a decision was made on operative treatment - repeat prosthetic repair of the abdominal aorta with a cadaveric allograft. At the Vascular Department of the Clinic of Faculty Surgery, laparotomy was performed, with removal of the infected graft, followed by debridement of the retroperitoneal space and repeat aortofemoral bifurcation prosthetic repair of the abdominal aorta with a cadaveric allograft. The wound healed with first intention. There was no evidence of infectious process relapse. The patient was discharged on postoperative day 15 in a satisfactory condition. The duration of follow up amounted to 6 months. The control examination showed that the pain-free walking distance was 500 m. Doppler ultrasonography demonstrated that the graft was functioning, with no signs of either anastomotic aneurysms or suppuration of the retroperitoneal space.

Xenogeneic materials for the surgical treatment of aortic infections

Background

The surgical treatment of aortic infections (AIs) is challenging. In situ aortic reconstructions represent nowadays the favored therapy for fit patients and xenogeneic materials are used increasingly. The aim of this study was to present our experience with xenogeneic reconstructions for AI using self-made bovine pericardium tubes and/or the biosynthetic Omniflow^® II graft.

Methods

This retrospective single-center study included all patients undergoing xenogeneic aortic and aortoiliac reconstructions from December 2015 to June 2020. Patient comorbidities, symptoms, procedural characteristics, types of pathogens and postoperative outcomes were analyzed.

Results

Twenty-eight patients [23 male (82%), median age 68 (range, 28–84) years] were included. Ten patients (36%) had native AIs and 18 (64%) had graft infections, including 3 (11%) aortoesophageal and 2 (7%) aortoduodenal fistulas (ADF). Twenty-four patients (86%) were symptomatic, the most common symptoms being contained aortic rupture (n=8) and sepsis (n=4). The surgical procedures were infra- and juxtarenal aortic repairs (n=11, 39% and n=7, 25%), thoracoabdominal aortic repairs (type IV: n=1, 4%; type V: n=3, 11%), descending thoracic aortic repairs (n=4, 14%) and 2 reconstructions (7%) involving the ascending aorta/aortic arch. Most were urgent (n=10, 43%) or emergent operations (n=11, 35%). Identification of pathogen(s), mostly Gram-positive bacteria, was possible in 25 patients (89%). Twelve patients (43%) had polymicrobial infections and 6 (21%) infections with multi-resistant bacteria. In-hospital mortality was 32% (n=9) due to acute cardiac failure (1/9), endocarditis (1/9), bleeding (3/9) and sepsis (4/9). The most frequent complications were transient need for dialysis (n=12, 43%) and persisting sepsis (n=11, 39%). Two early occlusions of Omniflow^® II grafts were observed (7%). Median follow-up (FU), during which 2 patients died of non-aortic causes, was 14 months (95% CI: 9–19 months). Freedom from reoperation was 100%, there was no evidence for reinfection during FU.

Conclusions

Xenogeneic orthotopic reconstructions for AI can be performed at all aortic levels. Combining bovine pericardium and the Omniflow^® II graft can be useful for reconstructing the branched aortic segments and both materials show appropriate early to midterm outcomes. Nonetheless, AIs are serious conditions associated with relevant morbidity/mortality rates, even in a specialized center.

Risk Factors for Mortality in Patients with Aortoesophageal Fistula Related to Aortic Lesions

Objective

Aortoesophageal fistula (AEF) related to aortic aneurysm and dissection is an uncommon but life-threatening condition. We performed a systematic review of risk factors for mortality and factors associated with the prognosis of AEF.

Methods

A systematic search of the PubMed, Embase, and Cochrane Library databases was performed. Clinical characteristics, diagnostic methods, and treatments were assessed in terms of their ability to predict mortality.

Results

The systematic review identified 184 eligible articles including 219 patients with AEF. Multivariable Cox regression revealed positive correlations of hemorrhagic shock (hazard ratio (HR): 1.824, 95% CI: 1.217-2.735, P = 0.004), sepsis (HR: 1.714, 95% CI: 1.112-2.641, P = 0.015), multiorgan failure (HR: 3.060, 95% CI: 1.470-6.368, P = 0.003), and conservative treatment (HR: 5.257, 95% CI: 3.405-8.116, P < 0.001) with mortality and a negative correlation between combination therapy (aortic graft replacement and esophagectomy) and mortality (HR: 0.319, 95% CI: 0.125-0.813, P = 0.017). Kaplan–Meier survival analysis showed that the 1-year cumulative survival rate was 42.5 ± 3.8%. The overall fistula-related mortality rate was 47.0% (103/219). The most common causes of death were bleeding (54.9%) and infection (29.2%).

Conclusions

We found that hemorrhagic shock, sepsis, and multiorgan failure were risk factors for death in patients with AEF. Additionally, conservative treatment was associated with a higher rate of mortality, while combined aortic graft replacement and esophagectomy improved the prognosis.

Successful surgical management of coarctation of the aorta with infective endaortitis and splenic abscess: a case report

Infective endaortitis with a splenic abscess is an extremely rare and fatal complication of coarctation of the aorta. We herein describe a 19-year-old female patient with a 2-month history of intermittent fever with progressive abdominal and leg pain. Aortic computed tomography angiography showed a rapidly progressive poststenotic saccular aneurysm immediately distal to the coarctation. Enhanced abdominal computed tomography showed a severe splenic abscess. During the operation, the infected spleen was resected first. We subsequently removed all of the diseased aorta and performed in situ aortic reconstruction with an artificial tube graft and without extracorporeal circulation. The patient had an uneventful postoperative clinical course and recovered very well during the 4-year follow-up. In summary, our case report details the successful surgical treatment of coarctation of the aorta with infective endaortitis and a splenic abscess and thoroughly discusses the indications and key notes for surgery without extracorporeal circulation in this complex disease.

Cryopreserved Allografts for Treatment of Chronic Limb-Threatening Ischemia in Patients Without Autologous Saphenous Veins

BACKGROUND

Revascularization is the best alternative to reduce symptoms and to improve the limb salvage rate in patients with chronic limb-threatening ischemia (CLI). Alternative grafts as synthetic prostheses and allografts must be considered for patients without a suitable autologous graft. Our aim was to evaluate outcomes of cryopreserved allografts used as a vascular conduit for bypass surgery in the infrainguinal territory.

METHODS

A retrospective analysis (January 1995 to January 2014) of the Registry of vascular and valvular allografts transplant in the autonomous community of Catalonia, Spain was performed for identifying patients with CLI who required infrainguinal bypass with cryopreserved arterial allografts. Statistical analysis was performed using SPSS, ver. 20, for Mac (Chicago).

RESULTS

A total of 149 patients with CLI (mean age of 70.1 years) were analyzed. One hundred two patients (68.5%) had a grade IV lesion (Fontaine classification). In the overall follow-up, 24.8% of patients required a reintervention. Overall graft occlusion, infection, and dilation rate were 52.3%, 6%, and 5.4% respectively. Overall 30-day mortality was 0.7%. Five-year primary patency rate and limb salvage rate were 38.6% and 50.2%, respectively. Survival rate at 5 years was 54.2%. Major adverse limb event (MALE)-free rate was 21.5% at 5 years. Revascularization to a distal target vessel was an independent positive predictive risk factor for a lower limb salvage rate and lower primary patency rate. Dyslipidemia was related to a lower limb salvage rate and represents a risk factor involved in MALEs.

CONCLUSIONS

Although arterial allografts seem to represent a suboptimal alternative, some selected patients could beneficiate from them. Five-year results are disappointing, and more studies are required to know other predictive factors for better selection of patients.