Dacron Vascular Grafts Research Articles

(177) FUSED DOUBLE-CYLINDER PENILE PROSTHESIS PLACEMENT AFTER PHALLOPLASTY WITHOUT URETHRAL LENGTHENING: A NOVEL TECHNIQUE USING A 2-PIECE IPP

Abstract Introduction Transgender men (TM) undergoing phalloplasty commonly desire erections for sexual activity. All U.S. FDA-approved inflatable penile prostheses (IPPs) are designed for cisgender anatomy. There is no gold-standard IPP-insertion technique post-phalloplasty. For TM seeking phalloplasty who don’t prioritize urinating from their penis-tip, phalloplasty without urethral lengthening (P-UL) offers similar cosmetic and functional outcomes with significantly lower risk-profiles. Also, the absence of a neourethra within the shaft affords sufficient room for 2-cylinders, instead of just one. Objective To describe 1) Our technique for insertion of a 2-piece IPP in TM using a fused, double-cylinder technique, and 2) To evaluate our outcomes over a 6-year period. Methods 1) Retrospective, single-center chart review of TM undergoing IPP insertion post-phalloplasty over 6-years. 2) We illustrate our technique for placement of 2-piece AMS Ambicor™ IPP using 2-cylinders, for TM post-P-UL (URL: https://youtu.be/9u7MMP0li4g). Results 28 patients underwent 34 IPP-implants between April/2017-Oct/2023 (Mean Age = 40.8 years±13.8(SD). 17/28 (60.7%) patients underwent P + UL, and 11/28 (39.3%) underwent P-UL. All had ipsilateral testicle prosthesis implant beforehand. IPP implants used were AMS 700™ 3-piece (first 5/34 = 14.7%; all 1 cylinder), or AMS Ambicor™ 2-piece IPP (all subsequent 29/34 = 85.3%; [22/29 (76%) = 1 cylinder and 7/29(24%) = 2 cylinders). 2/34(5.9%) IPP’s required explant: infection, 1/38(2.9%); and traumatic-injury wound-dehiscence 3-weeks postoperatively: 1/38(2.9%). Our technique for 2-piece IPP insertion in TM after P-UL: (Fig. 1). Both cylinders fitted completely into a Dacron vascular graft is secured to Obturator ramus with 2-0 Ethibond sutures. The IPP pump fits into the explanted testicle site. Conclusions Our “2-cylinders in a single sock” technique has key advantages: 1. Pre-IPP ipsilateral testicle implant expands the neoscrotum, making a capsule-lined pocket to protect the pump; 2. The Dacron vascular-graft fuses and allows anchoring of both cylinders, increasing stability/reducing migration; 3. Two-cylinders yield a more symmetric-appearing, fuller erection (+17% erection girth); 4. Our small, 4-cm parascrotal incision provides adequate exposure, and maintains good cosmesis. The approach we describe here provides excellent functional and cosmetic results. Disclosure No.

ИЗМЕНЕНИЯ БИОХИМИЧЕСКИХ ПОКАЗАТЕЛЕЙ КРОВИ У КРЫС ЛИНИИ WISTAR ПОСЛЕ ИМПЛАНТАЦИИ ФРАГМЕНТОВ СОСУДИСТЫХ ПРОТЕЗОВ

Background. This article deals with the use of biological vascular grafts made from bovine xenopericardium as a plastic material for reconstructive operations on the great vessels, which is one of the most important topics in modern vascular surgery. Aim. To compare changes in blood biochemical parameters in Wistar rats after implantation of fragments of biological and synthetic vascular grafts. Material and methods. The experimental study was performed on male laboratory Wistar rats (n = 50). The animals were divided into two groups: group 1 included 25 animals with implantation of a Dacron vascular graft; group 2 was composed of 25 animals with implantation of a vascular graft made from bovine xenopericardium. Blood samples from the laboratory rats were collected on days 3, 7, 14, 21 and 30 after the operation. Plasma urea, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase levels were measured. Results. No clinically significant changes in concentrations of low molecular weight metabolites of nitrogen metabolism or liver enzymes activity, alkaline phosphatase and lactate dehydrogenase activity were observed after implantation of a biological vascular graft from bovine xenopericardium compared to the animals with implanted synthetic vascular graft. Conclusion. The use of a biological vascular graft made from bovine xenopericardium does not cause clinically significant changes in blood biochemical parameters in laboratory rats.

A Case of Endovascular Aneurysm Repair for Non-anastomotic Pseudoaneurysm in Dacron Vascular Graft for Abdominal Aortic Aneurysm Which is Diagnosed with 4-dimentional Computed Tomography

A Case of Endovascular Aneurysm Repair for Non-anastomotic Pseudoaneurysm in Dacron Vascular Graft for Abdominal Aortic Aneurysm Which is Diagnosed with 4-dimentional Computed Tomography

Evaluation of the original sealant with antibacterial effect for synthetic vascular grafts

Background: Vascular graft infection is a severe cardiovascular complication with high mortality rates. Antibacterial vascular graft coatings are widely used and continue to be improved.Objective: To develop a sealant with antimicrobial effect for Dacron vascular grafts and experimentally test the coating properties.Methods: We used 2 types of vascular grafts: graft No. 1 (plain weave) with initial water permeability of 78.8 ± 2.7 mL/cm2/min and graft No. 2 (2/1 twill + 6/4 satin weave) with water permeability of 549.8 ± 20.7 mL/cm2/min. We developed an original gelatin impregnation technique, tested it using a scanning electron microscopy, and measured water permeability and kink radius. We evaluated the antibacterial activity of vancomycin and gelatin impregnation by the disk diffusion test using media with Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and measured inhibition zones after 24-hour incubation. We used samples cut out of grafts with vancomycin-containing (experimental group) and no vancomycin-containing (control group) impregnation.Results: The gelatin coating of the samples is visualized as a thin even film and provides zero water permeability. On the negative side, it increased stiffness and the kink radius. Thanks to vancomycin added to the coating, bacterial growth significantly inhibits: the mean diameter of the growth inhibition zone for Staphylococcus aureus and Enterococcus faecalis was 15.60 ± 0.65 and 14.40 ± 0.66 mm, respectively. The grafts untreated with vancomycin showed no growth inhibition zones.Conclusion: Vascular graft treatment with gelatin impregnation and vancomycin solution is a simple measure to prevent the growth of gram-positive bacteria on vascular grafts. Received 14 November 2022. Revised 15 December 2022. Accepted 19 December 2022. Funding: The work was supported by Russian Science Foundation (project No. 22-15-20005). Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: I.Yu. Zhuravleva, A.A. Shadanov, D.A. SirotaData collection and analysis: A.A. Shadanov, L.M. Samoylova, S.V. Vladimirov, T.P. Timchenko, N.E. Luchnikov, E.V. KarpovaStatistical analysis: A.A. ShadanovDrafting the article: A.A. Shadanov, L.M. Samoylova, T.P. Timchenko, A.G. EdemskiyCritical revision of the article: D.A. Sirota, I.Yu. Zhuravleva, A.V. Bogachev-Prokofiev, A.M. ChernyavskiyFinal approval of the version to be published: A.A. Shadanov, I.Yu. Zhuravleva, L.M. Samoylova, T.P. Timchenko, S.V. Vladimirov, E.V. Karpova, N.E. Luchnikov, D.A. Sirota, A.G. Edemskiy, A.V. Bogachev-Prokofiev, A.M. Chernyavskiy

BioGlue® is not associated with polypropylene suture breakage after aortic surgery.

ObjectiveWe have encountered broken or damaged polypropylene sutures (Prolene®) at the anastomotic sites during aortic reoperations. Because a surgical sealant, bovine serum albumin-glutaraldehyde (BioGlue®), was used in previous aortic surgery in some of these cases, we undertook this in vitro study to evaluate whether the use of BioGlue® was associated with breakage of polypropylene sutures at the aortic anastomosis.Materials and methodsThe broken polypropylene sutures, anastomotic sites and aortic tissue at the location of suture breakage were visually inspected and evaluated intraoperatively. Six human cadaveric aortic samples were incised circumferentially and anastomosed proximally to a valved conduit with running 4–0 polypropylene sutures (Prolene®). In the test group (n = 3), BioGlue® was applied directly to the Prolene® sutures at the anastomotic sites, while in the control group (n = 3) the anastomoses were not sealed with any surgical adhesive. The six samples were immersed in Dulbecco's phosphate buffered saline solution and mounted on a M-6 Six Position Heart Valve Durability Testing System and tested up to 120 million cycles for a 2-year period. During and upon completion of the testing, the integrity of Prolene® sutures, the anastomosis and aortic tissues was regularly assessed by visual inspection.ResultsIntraoperative findings included a stretched and thin aortic wall (some with thrombus), a small cleft between the aortic tissue and the Dacron vascular graft. An excessive amount of BioGlue® was often found around the anastomosis, with cracking material, but no signs of mechanical damage were observed in these cases. Upon visual inspection during and after in vitro testing, there was no apparent damage to the polypropylene sutures on the interior or exterior of the aortic anastomoses in any of the samples. No difference was observed in the physical integrity of the polypropylene sutures at anastomotic lines, the anastomoses and aortic tissues between the test and control samples.ConclusionsThe results of this study suggest that the use of BioGlue® was not associated with breakage of the polypropylene sutures at the anastomotic sites after aortic dissection repair.

A novel technique with Dacron vascular graft augmentation for knee extensor mechanism repairs: Technical note

Ruptures of the extensor apparatus can have different etiologies and be complicated by underlying situations. Direct repair is not always possible, and reconstruction procedures can be insufficient, which leads to the appearance of multiple augmentation techniques to improve the strength of these constructs. Despite the proven results of these techniques, numerous procedures are described without any gold standard. We present our augmentation method for repairing the knee extensor apparatus with a vascular prosthesis that facilitates healing, does not interfere with the primary procedure, has no donor morbidity or rejection risk, and allows earlier mobilization and rehabilitation. The technique was used in different cases with multiple etiologies that needed reinforcement, with promising results.

1164. In vitro Antimicrobial Efficacy of Novel Antimicrobial Dacron Vascular Grafts in the Inhibition of Multidrug-Resistant Gram-Negative Biofilm

BackgroundVascular graft infections can be a devastating complication in vascular reconstructive surgery. Management of these infections is highly invasive and includes excision of the graft, debridement of infected material, and in situ reconstruction. There is a need for additional strategies for infection prevention in graft surgeries. The minocycline + rifampin + chlorhexidine (MRCH) triple combination had been previously demonstrated to be effective against biofilm formation in central venous catheters. In this study, we evaluated in vitro effectiveness and durability of MRCH coated Dacron vascular grafts in inhibiting multidrug-resistant Gram-negative biofilm formation.MethodsDacron vascular grafts were coated with MRCH based on a proprietary method. Antimicrobial efficacy at baseline and 3-week durability was assessed using a well-established in vitro biofilm colonization model. Multidrug-resistant Gram-negative pathogens tested include CRE Escherichia coli (EC), MDR Pseudomonas aeruginosa (PS) and CRE Klebsiella pneumoniae (KB). Antimicrobial durability was assessed for grafts that had been eluting in serum for 3 weeks prior to testing. Baseline and 3-week grafts were quantitatively culture to enumerate any biofilm viable biofilm colonization. Uncoated Dacron grafts were used as controls.ResultsAt baseline and 3 weeks MRCH vascular grafts completely inhibited biofilm formation resulting in an 8-log10 reduction in bacterial colonization compared with uncoated grafts.ConclusionMRCH coated Dacron vascular grafts demonstrated in vitro effectiveness for at least 3 weeks in preventing biofilm colonization by multidrug-resistant Gram-negative pathogens. Further in vivo testing is warranted. Disclosures All authors: No reported disclosures.

Invited commentary

This basic science study's goal is to address an area of clinical ambiguity: how to coat an endovascular stent graft with rifampin in a standard and optimized manner for immediate use in an infected field. It optimizes two variables, concentration and incubation period, in an ex vivo experiment and on the basis of the results suggests a rapid real-time perioperative protocol. The graft chosen to study is a standard Dacron endograft of various diameters and lengths. There are reports of using a rifampin-coated endograft in an infected field with preparation extrapolated from methods used during open operation (60 mg/mL rifampin incubated for 1 hour). A dedicated scientific study to determine optimal endograft coating would allow a more reasonable comparison of results when applied in the clinical condition. This study demonstrates that a rifampin solution of 10 mg/mL delivered as one 20-mL aliquot with an incubation time of 10 minutes will provide a well-coated endograft, not improved by higher concentrations or longer periods of intubation. This allows the surgeon to save both resources (drug, supplies) and time during an urgent or emergent case. An overnight bathing in methanol solvent demonstrates that the concentration or incubation time had no effect on the amount of rifampin trapped (coating) on the graft. Bathing in a saline bath demonstrates that the coated rifampin is essentially gone at 50 hours. The well-coated endograft does not retain as much rifampin as a similarly coated control graft, probably because the control graft is a gelatin-sealed graft. The endograft is not made with a gelatin coating, so the authors have no control of this processing step, and the comparison is somewhat artificial. As with most good basic research, more questions come to mind than are answered by the original work. This study does not evaluate the prepared graft under conditions that might greatly influence its performance in the clinical situation. The lack of evaluation in a flow chamber does not allow an estimate of rifampin loss over time from both the flow and sac surface. Dacron endografts generally leak through the material interstices until anticoagulation is reversed, so the loss may be rapid from both surfaces. Under such circumstances, what antimicrobial activity remains even minutes after deployment? In vivo animal experiments with implantation in an infected field would yield some estimate of the potential clinical impact of this method of in situ repair. Would presealing with a gelatin coating before rifampin coating better mimic the open scenario and improve the results? All these factors being considered, this study does provide a logical basic science first step to a clinical problem that can now be further studied to provide greater insight into its clinic use. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysmsJournal of Vascular SurgeryVol. 69Issue 1PreviewIn the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol. Full-Text PDF Open Archive

Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysms

ObjectiveIn the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol. MethodsSeveral prepared rifampin solutions, including a negative control solution, were used to coat multiple triplicate sets of Dacron endovascular aortic stent grafts at different but set incubation periods. Rifampin elution from the grafts was studied by spectroscopic analysis. Once an optimized solution concentration and incubation time were determined, the elution of rifampin over time from the graft and the graft's surface characteristics were studied by ultraviolet-visible spectroscopy and atomic force microscopy. ResultsAll coated ESGs with any concentration of prepared rifampin solution, regardless of incubation time, immediately demonstrated a visible bright orange discoloration and subsequently after elution procedures returned to the original noncolored state. At the 25-minute incubation time (standard flush), there was no statistical difference in the amount of rifampin coated to the ESGs with 10-mg/mL, 30-mg/mL, and 60-mg/mL solutions (0.06 ± 0.01, 0.07 ± 0.05, and 0.044 ± 0.01, respectively; P > .05). This was also true for a 10-minute incubation time (express flush) of 10-mg/mL and 60-mg/mL rifampin solution concentrations (0.04 ± 0.007 and 0.066 ± 0.014, respectively; P = .22). The elution-over-time of coated rifampin ESG, although not statistically significant, did seem to plateau and to reach a steady state by 50 hours and was confirmed by surface characteristics using atomic force microscopy. ConclusionsHaving studied two variables of rifampin coating techniques to Dacron ESGs, the authors propose a rapid real-time perioperative coating protocol by using a 10-mg/mL rifampin solution for a 10-minute incubation period. As rifampin loosely binds to Dacron ESGs by weak intermolecular forces, a rifampin-coated ESG would need to be inserted in a timely fashion to treat the diseased aorta and to deliver its antibiotic affect. A rapid perioperative coating protocol followed by immediate deployment makes our proposed technique especially useful in an urgent and unstable clinical scenario.

Mechanical characterisation of Dacron graft: Experiments and numerical simulation

Experimental and numerical analyses focused on the mechanical characterisation of a woven Dacron vascular graft are presented. To that end, uniaxial tensile tests under different orientations have been performed to study the anisotropic behaviour of the material. These tests have been used to adjust the parameters of a hyperelastic anisotropic constitutive model which is applied to predict through numerical simulation the mechanical response of this material in the ring tensile test. The obtained results show that the model used is capable of representing adequately the nonlinear elastic region and, in particular, it captures the progressive increase of the rigidity and the anisotropy due to the stretching of the Dacron. The importance of this research lies in the possibility of predicting the graft׳s mechanical response under generalized loading such as those that occur under physiological conditions after surgical procedures.

Circumferential Fence With the Use of Polyethylene Terephthalate (Dacron) Vascular Graft for All-in-One Hepatic Venous Reconstruction in Right-Lobe Living-Donor Liver Transplantation

Integration of hepatic vein tributaries with a diameter ≥5 mm into the drainage system in right-lobe living-donor liver transplantation (LDLT) is of vital importance for graft function. Recently, the most commonly emphasized hepatic venous reconstruction model is the all-in-one reconstruction model. In the final stage of this model that aims to form a common large opening, allogeneic vascular grafts are almost always used to construct a circumferential fence. To date, no other study has reported the use of polyethylene terephthalate (Dacron) vascular graft as a circumferential fence in LDLT. We aimed to present the 1st 4 cases of circumferential fences created with Dacron vascular graft. Four right-lobe grafts weighing 522–1,040 g were used. A polytetrafluoroethylene vascular graft was used for the integration of segment 5 vein and segment 8 vein into the drainage model, whereas a Dacron graft was used to creating a circumferential fence. The patency of hepatic outflow evaluated with the use of multidetector computerized tomography at postoperative day 7. Venous outflow obstruction was not detected in any cases. This study suggested that owing to its flexible structure the polyethylene terephthalate vascular graft can be an alternative to allogeneic vascular grafts in forming circumferential fence.

18F-FDG Uptake in Noninfected Prosthetic Vascular Grafts: Incidence, Patterns, and Changes over Time

(18)F-FDG PET/CT is of value in the diagnosis of prosthetic vascular graft infection, but potential pitfalls related to tracer uptake in noninfected implants have been described. The current study assesses the incidence and patterns of (18)F-FDG uptake over time in noninfected grafts, in relationship to prosthetic material and location. A 12-y PET/CT database was retrospectively searched for cancer patients with prosthetic vascular grafts. Data retrieved from patient files included graft location, material, and time from surgery. Images were reviewed by 2 nuclear medicine physicians in consensus, with the presence and patterns (focal, diffuse homogeneous, inhomogeneous) of increased (18)F-FDG uptake in grafts recorded. The mean standardized uptake value in grafts (SUV-G) and mediastinum (SUV-M) was measured. The ratio of SUV-G to SUV-M (SUV-G/SUV-M) was calculated for each graft. One hundred seven prostheses were identified in 102 studies in 43 cancer patients. Sixty-seven prostheses were made of Dacron, 33 of Gore-Tex, and 7 were native veins. No increased (18)F-FDG uptake was found in 9 grafts (native veins, 4; Gore-Tex, 3; Dacron, 2). There was diffuse homogeneous uptake in 68 and inhomogeneous uptake in 30 grafts. The homogeneous pattern was more prevalent in Gore-Tex whereas the inhomogeneous uptake was seen more in Dacron vascular grafts. None of the grafts demonstrated focal uptake. The SUV-G range was 0.4-6.3 (average, 1.9), and SUV-M range was 0.6-2.4 (average, 1.4). The intensity of uptake was significantly higher in Dacron (SUV-G = 2.35 and SUV-G/SUV-M = 1.72) than in Gore-Tex (SUV-G = 1.09, SUV-G/SUV-M = 0.91) and native vein grafts (SUV-G = 1.07, SUV-G/SUV-M = 0.75) (P < 0.005). Native vein grafts showed a significant decrease in (18)F-FDG uptake over time whereas synthetic grafts showed no change in intensity for a follow-up of up to 16 y. Diffuse (18)F-FDG uptake was found in 92% of noninfected vascular prostheses, more in Dacron grafts than with other materials. The intensity of (18)F-FDG uptake of synthetic grafts did not change over time. With knowledge of the presence, patterns, and persistence of (18)F-FDG uptake in noninfected vascular prostheses, misinterpretation of PET/CT studies in patients referred for suspected prosthetic infection and in those assessed for diseases unrelated to their graft status can be avoided.

The in vitro research of bacterial invasion of prosthetic vascular grafts: comparison of elastomer-sealed and gelatin-coated Dacron vascular grafts

PurposeTo investigate the process of bacterial invasion from the surface to inside prosthetic vascular grafts.MethodsElastomer-sealed Dacron vascular grafts (ESDVGs) and gelatin-coated Dacron vascular grafts (GCDVGs) were cut into 6-cm segments and placed in a U-shaped configuration on culture plates. Physiological saline was poured inside the grafts and a suspension of Pseudomonas aeruginosa was added to the outside. Samples taken from inside the grafts at nine time points for up to 60 h were spread on agar. Bacterial colonies were then analyzed. The grafts were also examined using scanning electron microscopy (SEM).ResultsContaminated vascular graft models were produced in 18 ESDVGs (group T) and 12 GCDVGs (group G). The bacterial counts inside the vascular grafts in both groups increased over time. Bacterial colonies were confirmed in all samples from group G by 30 h, whereas bacteria appeared inside the grafts from group T at various times between 0 and 60 h. Bacteria were undetectable in one model from group T throughout the study. SEM revealed that the elastomeric membrane in the ESDVG was uneven.ConclusionBacterial invasion of vascular grafts does not always occur immediately after contamination. ESDVGs may be more resistant to bacterial invasion as they have a thicker and evenly enriched elastomeric membrane.

Retrohepatic vena cava deroofing in living donor liver transplantation for caudate hepatocellular carcinoma

The removal of tumor together with the native liver in living donor liver transplantation for hepatocellular carcinoma is challenged by a very close resection margin if the tumor abuts the inferior vena cava. This is in contrast to typical deceased donor liver transplantation where the entire retrohepatic inferior vena cava is included in total hepatectomy. Here we report a case of deroofing the retrohepatic vena cava in living donor liver transplantation for caudate hepatocellular carcinoma. In order to ensure clear resection margins, the anterior portion of the inferior vena cava was included. The right liver graft was inset into a Dacron vascular graft on the back table and the composite graft was then implanted to the recipient inferior vena cava. Using this technique, we observed the no-touch technique in tumor removal, hence minimizing the chance of positive resection margin as well as the chance of shedding of tumor cells during manipulation in operation.

S165 An alternative for short renal vein during kidney transplantation: Long-term experience with Polyethylene Terephthalate (Dacron) Vascular Graft

S165 An alternative for short renal vein during kidney transplantation: Long-term experience with Polyethylene Terephthalate (Dacron) Vascular Graft

Silver acetate coating promotes early vascularization of Dacron vascular grafts without inducing host tissue inflammation

Silver acetate is frequently used as an antimicrobial coating of prosthetic vascular grafts. However, the effects of this coating on the early inflammatory and angiogenic host tissue response still remain elusive. Therefore, the aim of the present invivo study was to analyze the biocompatibility and vascularization of silver acetate-coated and uncoated vascular grafts during the initial phase after implantation. Two different prosthetic vascular grafts (ie, uncoated Dacron and silver acetate-coated Dacron Silver) were implanted into the dorsal skinfold chamber of C57BL/6 mice (n= 8 per group) to study angiogenesis and leukocytic inflammation at the implantation site by means of repetitive intravital fluorescence microscopy over a 14-day period. At the end of the invivo experiments, collagen formation, apoptosis, and cell proliferation were analyzed in the newly developed granulation tissue surrounding the implants by histology and immunohistochemistry. During the initial 14 days after implantation, Dacron Silver exhibited an improved vascularization, as indicated by a significantly increased functional capillary density compared with Dacron. This was not associated with a stronger leukocytic inflammatory host tissue response to the implants. Moreover, silver acetate coating did not affect collagen formation, apoptosis, and cell proliferation at the implantation site. Silver acetate coating of prosthetic vascular grafts improves their early vascularization without inducing severeinflammatory side effects. Accordingly, this material modification crucially contributes to an improved incorporation of the implants into the host tissue, which may decrease the risk of vascular graft infection.

A rare long-term Dacron graft complication: Pseudoaneurysm formation and graft deformation

Dacron vascular grafts have been used safely since decades. However, long terms complications including organ loss or death may be observed. Evaluation of the graft using ultrasonography and computed tomogra- phy in asymptomatic cases is beneficial particularly in early diagnosis of the late vascular graft complications. We present a 57 year old male patient who underwent femoro-popliteal by-pass 8 years ago, and developed deformity and pseudoaneurysm at the non-anastomotic site on dacron-graft who was successfully treated with endovascular intervention. Although surgical treatment is employed in first place among treatment modalities, advancements in percutaneous interventional methods and diversity of the materials used have constituted these interventions as alternatives of surgical treatment.

Temporary Right Heart Assist: A Minimally Invasive Approach

A surgical method for the implantation of a mechanical right ventricular assist device which avoids resternotomy/thoracotomy and related complications at the time of explantation is presented. In order to support the failing right heart, a Dacron vascular graft was sewn to the pulmonary artery. For venous drainage, a cannula was inserted into the right atrium via the femoral vein. Explantation of the system, after the right heart resumed its function, was accomplished by retracting and compressing the venous cannula in the groin as well as by retracting the arterial cannula from the Dacron vascular graft followed by suturing without opening the chest. Between 2006 and 2011, this system was used in 12 patients. The median duration of right heart support was 10.5 days. Seven patients were successfully weaned from the system, six patients survived. In all cases, explantation was free of complications. The technique described is a safe method to support the right heart and allows explantation without the risks and complications of reopening the thorax.

Dynamic Changes of Smooth Muscle and Endothelial Markers in the Early Healing Process of Dacron Vascular Grafts in the Dog, Using RT-PCR.

Previous studies of neointima formation on Dacron vascular grafts mainly focused on the late stages using immunohistochemistry staining for von Willebrand factor (vWF) and smooth muscle (SM) alpha-actin. However, it is impossible to use immunohistochemistry to study the early events of neointima formation, because graft samples lack sufficient cellular material. Therefore, we used reverse transcriptase-polymerase chain reaction (RT-PCR) to demonstrate dynamic changes of SM and endothelial markers during the early stages of neointima formation. Preclotted Dacron grafts were implanted in the descending thoracic aorta of 14 mongrel dogs. Specimens were retrieved at 1-4 weeks. Total RNAs were extracted from mid-portion of graft flow surfaces, and RT-PCR for vWF, SM myosin heavy chain (MHC), and SM alpha-actin were performed and expressed as a ratio to the ribosome s17 signal. SM MHC and vWF mRNA expression was low at 1-2 weeks but elevated at 3-4 weeks (P < 0.05). However, SM alpha-actin mRNA levels were expressed consistently throughout the study period. At 3-4 weeks, vWF mRNA expression was inversely correlated to thrombus formation on the graft flow surface. Increased expressions of SM MHC and vWF mRNA corresponded to the formation of neointima and an endothelial layer at the later stages. However, SM alpha-actin mRNA expression did not vary during the healing process. The application of RT-PCR should permit further studies of gene regulation in the early vascular graft healing process in vivo. This model can also be used to study the molecular events that are involved in SM cell differentiation.

An Evolving Role of Anesthesiologists in the Management of Thoracic Aortic Diseases

Thoracic aortic diseases are a spectrum of medical conditions for which surgery is the definitive treatment. For that reason, anesthesiologists are likely to encounter patients with thoracic aortic diseases and have an important role in their care. The importance of the anesthesiologist was recognized in the 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients with thoracic aortic disease appearing in this issue of the journal and originally published in Circulation. In this first iteration, The Society of Cardiovascular Anesthesiologists (SCA) and 9 other medical societies worked together to create a multidisciplinary set of guidelines for screening, diagnosis, and treatment of patients with thoracic aortic diseases. Together, we believe that guidelines are most valuable to clinicians when they are disease focused rather than specialty focused or intervention focused. By providing detailed, accessible guidelines for the detection, diagnosis, and management of thoracic aortic diseases, the American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) also addressed the publicity generated by the death of John Ritter, a well known actor who died on September 11, 2003 of an acute aortic dissection. After his death, John Ritter’s widow, also an actress, filed a wrongful death lawsuit against the physicians who had failed to diagnose and immediately treat her husband’s condition. Although she did not win the lawsuit, she stated that the case was important because it brought together experts and raised public awareness about aortic disease. “I don’t know what you call it in medicine, but in acting or art, it would be called a master class. The most brilliant minds in the aorta business were there.”* In the same year, beginning in January 2003, The Wall Street Journal published a series of articles to bring attention to the incidence of aortic disease and the absence of any organized effort on a national level to identify and treat patients with these conditions.† These articles, by Kevin Helliker and Thomas Burton, had provocative titles such as, “A Death Sentence You Can Avoid,” “Ordering an Autopsy Could Save Your Life,” and “Knowledge Gap. Medical Ignorance Contributes to the Toll from Aortic Illness. Many Doctors Don’t Realize Aneurysms Are Treatable; a Paucity of Experts.” From a physician’s perspective, the articles were especially haunting. Kevin Helliker, an avid triathlete, described vividly in first hand what it was like to be diagnosed with a thoracic aortic aneurysm at the age of 43 years and the inevitable lifestyle changes and decisions that he will have to face. In 2004, the Pulitzer Prize for Explanatory Reporting was awarded to Kevin Helliker and Thomas Burton “for their groundbreaking examination of aneurysms, an often overlooked medical condition that kills thousands of Americans each year.” One such American, Michael DeBakey, the cardiac surgeon who pioneered the use of the Dacron vascular graft for aortic repair and whose name is used in the nomenclature for classifying aortic dissections, almost died from an aortic dissection in 2005. This publicity, together with the publication of the guidelines from the ACCF and AHA, will increase the public’s expectations and the responsibilities of health care providers for diagnosing and managing patients with thoracic aortic diseases. Improved screening and early diagnosis of thoracic aortic diseases would provide little benefit if the prospects for surgical repair were only marginally better than the consequences of the disease itself. Undertaking operations on the thoracic aorta, the conduit for blood to the entire body, is a serious commitment with inherent risks. Strategies to protect the heart, brain, spinal cord, and mesenteric organs from ischemic injury are necessary to ensure successful operations. Fortunately, cardiothoracic surgeons together with anesthesiologists have accomplished much to improve the safety and outcome of these operations. Some examples of specialized organ-protection strategies advocated by the guidelines include: (a) deep hypothermic circulatory arrest, antegrade cerebral perfusion, and retrograde cerebral perfusion alone or in combination to minimize brain injury (section 14.5.1); (b) cerebrospinal fluid drainage and spinal cord perfusion pressure optimization From the Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania.