Hybrid approach of arterial allograft application in reconstructive surgery of the great arteries

The article presents a case of a hybrid intervention using an arterial allograft on the great arteries of the lower extremities in a patient with chronic limb threatening ischemia and prosthetic infection. The patient has a history of repeated operations using synthetic polytetrafluoroethylene and dacron prostheses. In the early postoperative period, a clinical presentation of the prosthesis bed suppuration developed. The article shows the main phases of patient treatment: removal of synthetic prostheses, transplantation of the donor femoral artery, and balloon angioplasty of the popliteal and anterolateral arteries. In the postoperative period, blood circulation in the lower limb is fully compensated, and the dorsal pedis artery pulse is determined. Wounds were healed by primary intention. At the control visit after 6 months, no adverse events were revealed; according to the data of duplex scanning, the main blood flow in the arteries of the leg was recorded, the blood circulation was fully compensated. Thus, hybrid intervention using arterial allograft and balloon angioplasty of the popliteal and anterolateral tibial arteries proved to be an effective method of treatment in the current clinical situation.

Prosthetic Subclavian-Aortic Bypass as a Safe Surgical Technique for the Coarctation of the Aorta in Adults

BACKGROUND: Coarctation represents 5-8% of congenital heart disease. Residual hypertension remains the main problem after late correction. Surgical treatment in the adult remains a challenge for the surgeon. Our prefered method used in this category is the Subclavian-aortic bypass.MATERIAL AND METHODS: We have reviewed our registry for the period of 12 years (1998- 2010) and we found a group of 18 adult patients being operated for coarctation of the aorta. The mean age of this group of patients was 24.7 ± 8.43 years (range 16-42 years). 13 were males and 5 females. RESULTS: Sugical technique: Most of the patients (13 pts, 72%) which were obviously treated with subclavian-aortic bypass with a Dacron prostheses. Mean preoperative and postoperative pressure gradients measured by echocardiography were 77.7 ± 20.16 mmHg and 22.3 ± 9.14 mmHg respectively. No mortality was observed in this series of patients. Chylothorax was the only complication observed in one patient in the early postoperative period.CONCLUSION: Coarctation of the aorta in adults is treated with optimal early results at our surgical centre. Subclavian-aortic bypass grafting requires less aortic dissection, can be performed with a partially occluding clamp, and does not compromise the spinal cord vascularization.

Urological complication following aortoiliac graft: case report and review of the literature

CONTEXT: Ureteral stenosis and ureterohydronephrosis may be serious complications of aortoiliac or aortofemoral reconstructive surgery. CASE REPORT: A 62-year-old female patient presented with a six-month history of left lumbar pain. She was a smoker, and had mild chronic arterial hypertension and Takayasu arteritis. She had previously undergone three vascular interventions. In two procedures, Dacron prostheses were necessary. Excretory urography showed moderate left ureterohydronephrosis and revealed a filling defect in the ureter close to where the iliac vessels cross. This finding was compatible with ureteral stenosis, and the aortoiliac graft may have been the reason for this inflammatory process. The patient underwent laparotomy, which showed that there was a relationship between the ureteral stenosis and the vascular prosthesis. Segmental ureterectomy and end-to-end ureteroplasty with the ureter crossing over the prosthesis anteriorly were performed. There were no complications. The early and late postoperative periods were uneventful. The patient evolved well and the results from a new excretory urogram were normal. We concluded that symptomatic ureterohydronephrosis following aortoiliac graft is a real complication and needs to be quickly diagnosed and treated by urologists.

Fluid Mechanics of Deformable Aortic Prostheses

The simultaneous replacement of a diseased aortic valve, aortic root and ascending aorta with a composite graft equipped with a prosthetic valve is a nowadays standard surgical approach in which the Valsalva sinuses of the aortic root are sacrificed and the coronary arteries are reconnected directly to the graft (Bentall procedure). In practice, two different polyethylene terephthalate (Dacron) prostheses are largely used by surgeons: a standard straight graft and a graft with a bulged portion that better reproduces the aortic root anatomy (Valsalva graft). The aim of the present investigation is to study the effect of the graft geometry, with its pseudo-sinuses, on the the flowfield, with particular attention to the coronary entry-flow, and on the stress concentration at the level of coronary-root anastomoses during the cardiac cycle. A bi-leaflet mechanical valve with curved leaflets is considered, attached to the two different prostheses. Two cylindrical channels, reproducing the very early coronary vasculature are connected to the grafts. An accurate three-dimensional numerical method, based on the immersed boundary technique, is proposed to study the flow inside deformable geometries. Direct numerical simulations of the flow inside the prostheses under physiological pulsatile inflow conditions are presented. The dynamics of the leaflets (considered rigid) is obtained by a fully-coupled fluid-structure-interaction approach, while a weak-coupled approach is employed for the deforming roots, in order to reduce the computational cost, using optimized solvers for both the fluid and structural problems. The Dacron material is modeled as orthotropic, with an inversion of the material properties in longitudinal and circumferential direction for the skirt region of the Valsalva prosthesis. Coronary perfusion is reproduced modulating in time the porosity, and thus the resistance, of the coronary channels. The results indicate that while the pseudo-sinuses do not significantly influence the coronary entry-flow, their presence allows for smaller levels of stresses at the level of coronary-root anastomoses, potentially reducing post-operative complications.

Mupirocin Prophylaxis against Methicillin-Susceptible, Methicillin-Resistant, or Vancomycin-IntermediateStaphylococcus epidermidis Vascular-Graft Infection

ABSTRACT A rat model was used to investigate the efficacy of mupirocin in the prevention of vascular prosthetic graft infection due toStaphylococcus epidermidis strains with different susceptibility patterns (methicillin susceptible, methicillin resistant, and with intermediate resistance to vancomycin). The effect of mupirocin-soaked Dacron was compared to that of perioperative intraperitoneal prophylaxis with vancomycin. Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses (1 cm2) followed by topical inoculation with 5 × 107 CFU of one staphylococcal strain. The study included a control group (no graft contamination), three contaminated groups that did not receive any antibiotic prophylaxis, three contaminated groups that received mupirocin-soaked grafts, three contaminated groups in which perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg of body weight) was administered, and three contaminated groups that received mupirocin-soaked grafts and perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg). The grafts were sterilely removed 7 days after implantation, and the infection was evaluated by using sonication and quantitative agar culture. Data analysis showed the efficacy of mupirocin against all three strains, with growth of the strains in treated rats significantly different than that in the untreated control. In addition, mupirocin was more effective than vancomycin against the strain with intermediate susceptibility to the glycopeptide. Finally, the combination of mupirocin and vancomycin produced complete suppression of the growth of all of the strains.