Use of Intraoperative Duplex Ultrasound and Resistance Index Reduces Complications in Living Renal Donor Transplantation.

BACKGROUND: The treatment of choice in end-stage renal disease is transplantation. Hemodynamic disturbances can evoke graft loss, while early ultrasound identification of vascular problems improves outcome. The aim of this study was to identify differences in postoperative complications with and without systematic intraoperative Doppler ultrasound use. METHODS: The primary outcome was the postoperative rate of complications and the secondary aim was to find a predictive resistance index cut-off value, which would show where surgical reintervention was necessary. Over a 10-year period, 108 renal transplants were performed from living donors at our institution. In group 1 (n = 67), intraoperative duplex ultrasound and intraparenchymatous resistance index measurements assessed patients, while in group 2 (n = 41), no ultrasound was performed. RESULTS: There were no intergroup differences in the overall postoperative complication rate or in benefit to graft or patient survival with Doppler use. However, significantly more vascular complications (10% vs 0%, P = .02) and more acute rejections (37% vs 10%) occurred in group 2 than in group 1. Therefore, an intraoperative cut-off value of the resistance index 0.5 was proposed to justify immediate surgical revision. CONCLUSIONS: This is the first report demonstrating benefits of systematic intraoperative Doppler ultrasound on postoperative complications in renal transplantation from living donors. Our results support surgical revision with a resistance index <0.5.

[Isolated true aneurysm of the deep femoral artery]. / Un anévrisme isolé de l'artère fémorale profonde.

Aneurysms of the deep femoral artery, accounting for 5% of all femoral aneurysms, are uncommon. There is a serious risk of rupture. We report the case of an 83-year-old patient with a painless pulsatile mass in the right groin due to an aneurysm of the deep femoral artery. History taking revealed no cardiovascular risk factors and no other aneurysms at other localizations. The etiology remained unclear because no recent history of local trauma or puncture was found. ACT angiography was performed, revealing a true isolated aneurysm of the deep femoral artery with a diameter of 90mm, beginning 1cm after its origin. There were no signs of rupture or distal emboli. Due to unsuitable anatomy for an endovascular approach, the patient underwent open surgery, with exclusion of the aneurysm and interposition of an 8-mm Dacron graft to preserve deep femoral artery flow. Due to their localization, the diagnosis and the management of aneurysms of the deep femoral artery can be difficult. Options are surgical exclusion or an endovascular approach in the absence of symptoms or as a bridging therapy. If possible, blood flow to the distal deep femoral artery should be maintained, the decision depending also on the patency of the superficial femoral artery. In case of large size, aneurysms of the deep femoral artery should be treated without any delay.

[What to expect from dialysis in the future?]. / Que peut-on attendre de la dialyse dans le futur?

The number of people with end stage kidney failure is increasing worldwide, mainly due to aging of the population. Hence the need for renal replacement therapy is continually expanding. Kidney transplantation, haemodialysis and peritoneal dialysis are currently the gold standard of renal replacement therapy. These three techniques have all their specific advantages and shortcomings. Facing the high complication rate of actual techniques, an increasingly migrant population and the growing desire to respect the environment, alternatives are needed. New techniques that might improve some of these points are in development and will be reviewed in this article.

[Treatment of critical lower limb ischemia]. / Traitement de l'ischémie critique chronique des membres inférieurs en 2014.

Critical limb ischemia is a major public health problem in our western countries due to the epidemia of (diabesity). The outcome of patients suffering from critical limb ischemia reains poor with an amputation free survival rate at one year of about 50%. The treatment should be multidiciplinary and done in emergency in specialized centers to ensure the limb salvage: this management should be centered aroud 3 axis: the screening of the cardiovascular risk factors, the best medical treatment and the invasive approaches. Due to multiple endovascular technical innovations, more frail patients with com plex diseases can be treated with good results. Therefore, the endovascular treatment is essential in the management of such patients by vascular surgeons.

Bone marrow mesenchymal stem cells stabilize already-formed aortic aneurysms more efficiently than vascular smooth muscle cells in a rat model.

PURPOSE: Abdominal aortic aneurysms (AAAs) expand because of aortic wall destruction. Enrichment in Vascular Smooth Muscle Cells (VSMCs) stabilizes expanding AAAs in rats. Mesenchymal Stem Cells (MSCs) can differentiate into VSMCs. We have tested the hypothesis that bone marrow-derived MSCs (BM-MSCs) stabilizes AAAs in a rat model. MATERIAL AND METHODS: Rat Fischer 344 BM-MSCs were isolated by plastic adhesion and seeded endovascularly in experimental AAAs using xenograft obtained from guinea pig. Culture medium without cells was used as control group. The main criteria was the variation of the aortic diameter at one week and four weeks. We evaluated the impact of cells seeding on inflammatory response by immunohistochemistry combined with RT-PCR on MMP9 and TIMP1 at one week. We evaluated the healing process by immunohistochemistry at 4 weeks. RESULTS: The endovascular seeding of BM-MSCs decreased AAA diameter expansion more powerfully than VSMCs or culture medium infusion (6.5% ± 9.7, 25.5% ± 17.2 and 53.4% ± 14.4; p = .007, respectively). This result was sustained at 4 weeks. BM-MSCs decreased expression of MMP-9 and infiltration by macrophages (4.7 ± 2.3 vs. 14.6 ± 6.4 mm(2) respectively; p = .015), increased Tissue Inhibitor Metallo Proteinase-1 (TIMP-1), compared to culture medium infusion. BM-MSCs induced formation of a neo-aortic tissue rich in SM-alpha active positive cells (22.2 ± 2.7 vs. 115.6 ± 30.4 cells/surface units, p = .007) surrounded by a dense collagen and elastin network covered by luminal endothelial cells. CONCLUSIONS: We have shown in this rat model of AAA that BM-MSCs exert a specialized function in arterial regeneration that transcends that of mature mesenchymal cells. Our observation identifies a population of cells easy to isolate and to expand for therapeutic interventions based on catheter-driven cell therapy.

Investigations of a thermosensitive gel to temporarily occlude crural arteries in femoro-distal bypass surgery.

OBJECTIVES: Long occlusions in calcified crural arteries are a major cause of endovascular technical failure in patients with critical limb ischaemia. Therefore, distal bypasses are mainly performed in patients with heavily calcified arteries and with consequently delicate clamping. A new reverse thermosensitive polymer (RTP) is an alternative option to occlude target vessels. The aim of the study is to report our technical experience with RTP and to assess its safety and efficiency to temporarily occlude small calcified arteries during anastomosis time. METHODS: Between July 2010 and December 2011, we used RTP to occlude crural arteries in 20 consecutive patients with 20 venous distal bypasses. We recorded several operative parameters, such as volume of injected RTP, duration of occlusion and anastomotic time. Quality of occlusion was subjectively evaluated. Routine on-table angiography was performed to search for plug emboli. Primary patency, limb salvage and survival rates were reported at 6 months. RESULTS: In all patients, crural artery occlusion was achieved with the RTP without the use of an adjunct occlusion device. Mean volume of RTP used was 0.3 ml proximally and 0.25 ml distally. Mean duration of occlusion was 14.4 ± 4.5 min, while completion of the distal anastomosis lasted 13.4 ± 4.3 min. Quality of occlusion was judged as excellent in eight cases and good in 12 cases. Residual plugs were observed in two patients and removed with an embolectomy catheter, before we amended the technique for dissolution of RTP. At 6 months, primary patency rate was 75% but limb salvage rate was 87.5%. The 30-day mortality rate was 10%. CONCLUSIONS: This study shows that RTP is safe when properly dissolved and effective to occlude small calcified arteries for completion of distal anastomosis.

[The complex aortic abdominal aneurysm: is open surgery old fashion?]. / Anévrismes complexes de l'aorte abdominale: la chirurgie ouverte est-elle obsolète?

Open surgery is still the main treatment of complex abdominal aortic aneurysm. Nevertheless, this approach is associated with major complications and high mortality rate. Therefore the fenestrated endograft has been used to treat the juxtarenal aneurysms. Unfortunately, no randomised controlled study is available to assess the efficacy of such devices. Moreover, the costs are still prohibitive to generalise this approach. Alternative treatments such as chimney or sandwich technique are being evaluated in order to avoid theses disadvantages. The aim of this paper is to present the endovascular approach to treat juxtarenal aneurysm and to emphasize that this option should be used only by highly specialized vascular centres.

Infrainguinal bypass for peripheral arterial occlusive disease: when arms save legs.

OBJECTIVES: Determine if arm veins are good conduits for infrainguinal revascularisation and should be used when good quality saphenous vein is not available. DESIGN: Retrospective study. MATERIALS AND METHODS: We evaluated a consecutive series of infrainguinal bypass (IB) using arm vein conduits from March 2001 to December 2006.We selected arm vein by preoperative ultrasound mapping to identify suitable veins. We measured vein diameter and assessed vein wall quality. We followed patients with systematic duplex imaging at 1 week, 1, 3, 6 and 12 months, and annually thereafter. We treated significative stenoses found during the follow-up. RESULTS: We performed 56 infrainguinal revascularisation using arm vein conduits in 56 patients. Primary patency rates at 1, 2 and 3 years were 65%, 51% and 47%. Primary assisted patencies at 1, 2 and 3 years were 96%, 96% and 82%. Secondary patency rates at 1, 2 and 3 years were 92%, 88% and 88%. The three-year limb salvage rate was 88%. CONCLUSIONS: We conclude that infrainguinal bypass using arm vein for conduits gives good patency rates, if selected by a preoperative US mapping to use the best autogenous conduit available.

Ex vivo pulsatile perfusion of human saphenous veins induces intimal hyperplasia and increased levels of the plasminogen activator inhibitor 1.

Vessel wall trauma induces vascular remodeling processes including the development of intimal hyperplasia (IH). To assess the development of IH in human veins, we have used an ex vivo vein support system (EVVSS) allowing the perfusion of freshly isolated segments of saphenous veins in the presence of a pulsatile flow which reproduced arterial conditions regarding shear stress, flow rate and pressure during a period of 7 and 14 days. Compared to the corresponding freshly harvested human veins, histomorphometric analysis showed a significant increase in the intimal thickness which was already maximal after 7 days of perfusion. Expression of the endothelial marker CD31 demonstrated the presence of endothelium up to 14 days of perfusion. In our EVVSS model, the activity as well as the mRNA and protein expression levels of plasminogen activator inhibitor 1, the inhibitor of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA), were increased after 7 days of perfusion, whereas the expression levels of tPA and uPA were not altered. No major change was observed between 7 and 14 days of perfusion. These data show that our newly developed EVVSS is a valuable setting to study ex vivo remodeling of human veins submitted to a pulsatile flow.

New insight in aetiopathogenesis of aortic diseases.

BACKGROUND: Knowledge in the aetiopathogeny of aortic disease helps to characterise aortic lesions better and determine the risk of evolution and therapeutic strategies as well. This article focusses on aneurysms and dissections, and excludes causes related to infection, systemic inflammatory diseases and trauma. METHODS AND RESULTS: The biomedical literature of the past 10 years has been reviewed here. Aortic diseases are heterogeneous along the aorta as far as their genetic determinants, contribution of smooth muscle cells, inflammation and thrombus formation are concerned. Degradation of extracellular matrix by proteases causing aortic disease is a 'terminal' event, modulated by genetic background, haemodynamic strain, cellular events and thrombus formation. New genetic determinants of aortic disease have been identified. Proteases degrading the aortic wall are derived from a variety of cell types in addition to macrophages, including neutrophils on the luminal thrombus, mesenchymal and endothelial cells in the wall. Smooth muscle cells contribute to aortic wall homeostasis against inflammation and proteolysis. The degradation of the wall is followed by, or paralleled with, a failure of aortic reconstruction. CONCLUSIONS: Aortic diseases are diverse, and involve a multiplicity of biological systems in the vascular wall and at the interface with blood. Future research needs to unravel distinct cellular and molecular mechanisms causing the clinical events, in particular, dissection, expansion of already formed aneurysms and rupture.

Clinical results of autologous infrainguinal revascularization using grafts originating distal to the femoral bifurcation in patients with mild inflow disease.

AIM: Chronic critical limb ischemia (CLI) often requires venous bypass grafting to distal arterial segments. However, graft patency is influenced by the length and quality of the graft and occasionally patients may have limited suitable veins. We investigated short distal bypass grafting from the superficial femoral or popliteal artery to the infrapopliteal, ankle or foot arteries, despite angiographic alterations of inflow vessels, providing that invasive pressure measurement at the site of the planned proximal anastomosis revealed an inflow-brachial pressure difference of

[Quality of life after superficial femoral vein harvest for infra-inguinal reconstructions]. / Evaluation de la qualité de vie après prélèvement de la veine fémorale superficielle lors de reconstructions infra-inguinales.

BACKGROUND: The superficial femoral vein (SFV) is a well-established alternative conduit for infra-inguinal reconstructivenous hypertension after SFV harvest may however result in significant morbidity. This study reports the efficiency of SFV as conduit for infra-inguinal reconstructions and characterize the anatomic and physiologic changes in harvest limbs and their relationship to the development of venous complications. METHODS: From May 1999 through November 2003, 23 SFV were harvested from 21 patients undergoing infra-inguinal reconstructions. Bypasses were controlled by regular duplex-ultrasound. The venous morbidity was assessed by measurements of leg circumferences, strain-gauge plethysmography and quality of life, investigated by the VEINES-QOL scale. RESULTS: At a mean follow-up of 10.4 months (range 1-56), primary, secondary patency and limb salvage rates of infra-inguinal bypasses using SFV are 71.4%, 76.2% and 85.7% respectively. No patient had major venous claudication. Oedema was significantly present in nine patients. Strain-gauge plethysmography showed outflow obstruction in all patients. The VEINES-QOL assessment showed no limitation in social and domestic activity, moderate complain about leg heaviness despite presence of oedema. CONCLUSION: The SFV harvest is a reliable conduit for infra-inguinal reconstructions and results in moderate venous morbidity in terms of functional consequences and quality of life.

Foot skin blood flow following infrainguinal revascularization for critical lower limb ischemia.

INTRODUCTION: The aim of this study was to assess the blood flow in the feet before and after lower limb revascularization using laser Doppler imaging (LDI). METHODS: Ten patients with critical lower limb ischemia were prospectively enrolled from June to October 2004. All patients underwent successful unilateral surgical interventions including above-knee bypass, distal bypass and endarterectomy. Skin blood flow (SBF) over the plantar surface of both forefeet and heels was measured by LDI 24h before and 10 days after revascularization, expressed in perfusion units (PU), and reported as mean+/-SD. RESULTS: Measurements in the forefoot and heel were similar. Before revascularization mean SBF was significantly lower in the ischemic foot (130+/-71 PU) compared to the contralateral foot (212+/-68 PU), p<0.05. After revascularization a significant increase of the SBF in the forefoot (from 135+/-67 to 202+/-86 PU, p=0.001) and hindfoot (from 148+/-58 to 203+/-83, p=0.001) was observed on the treatment side. However, a large decrease of the SBF was seen in forefoot and hindfoot on the untreated side (from 250+/-123 PU to 176+/-83 and from 208+/-116 to 133+/-40, p=0.001, respectively). CONCLUSION: This study confirms the benefits of revascularization in patients with nonhealing foot lesions due to critical limb ischemia. A significant increase of the SBF was observed on the treatment side. However, an unexpected decrease was observed on the untreated side.

Mechanisms of acrylamide formation: Maillard-induced transformation of asparagine.

The formation of acrylamide (AA) from L-asparagine was studied in Maillard model systems under pyrolysis conditions. While the early Maillard intermediate N-glucosylasparagine generated approximately 2.4 mmol/mol AA, the Amadori compound was a less efficient precursor (0.1 mmol/mol). Reaction with alpha-dicarbonyls resulted in relatively low AA amounts (0.2-0.5 mmol/mol), suggesting that the Strecker aldehyde pathway is of limited relevance. Similarly, the Strecker alcohol 3-hydroxypropanamide generated low amounts of AA (0.2 mmol/mol). On the other hand, hydroxyacetone afforded more than 4 mmol/mol AA, indicating that alpha-hydroxycarbonyls are more efficient than alpha-dicarbonyls in transforming asparagine into AA. The experimental results are consistent with the reaction mechanism proposed, i.e. (i) Strecker-type degradation of the Schiff base leading to azomethine ylides, followed by (ii) beta-elimination of the decarboxylated Amadori compound to release AA. The functional group in beta-position on both sides of the nitrogen atom is crucial. Rearrangement of the azomethine ylide to the decarboxylated Amadori compound is the key step, which is favored if the carbonyl moiety contains a hydroxyl group in beta-position to the N-atom. The beta-elimination step in the amino acid moiety was demonstrated by reacting under pyrolysis conditions decarboxylated model Amadori compounds obtained by synthesis.

Vacuum-assisted conservative treatment for the management and salvage of exposed prosthetic hemodialysis access.

Recurrent puncture of dialysis grafts can cause erosion and ulcer formation in the skin over the prosthetic material. Contamination of the wound can lead to infection of the graft, and the necessity to remove it. We describe four cases where agressive treatment with debridement, intravenous antibiotics and negative pressure therapy allowed prosthesis salvage without discontinuation of hemodialysis.

Comparison of morphological and functional alterations of human saphenous veins after seven and fourteen days of ex vivo perfusion.

Intimal hyperplasia (IH) is a vessel wall remodeling process responsible of early failure after vascular surgery or endovascular interventions. An ex vivo perfusion was used to study human venous segments regarding functional, histomorphological, immunohistochemical and molecular alterations after 7 (group 1, n = 6) and 14 days (group 2, n = 6) of ex vivo perfusion. All vessel segments showed preserved smooth muscle function before and after perfusion. Histomorphometry revealed IH development which was more pronounced after 14 days rather than 7 days (p < 0.05). Expression of CD34, factor VIII, alpha-actin and MIB-1 was demonstrated in all segments from both groups indicating that muscular and endothelial integrity was preserved after ex vivo perfusion of up to 14 days. PAI-1 mRNA expression was significantly increased after perfusion (p < 0.05), suggesting that the endothelial fibrinolytic function may be modulated in this ex vivo perfusion model of human saphenous veins.

Comparative assessment of intimal hyperplasia development after 14 days in two different experimental settings: tissue culture versus ex vivo continuous perfusion of human saphenous vein.

BACKGROUND: Intimal hyperplasia (IH) is a vascular remodeling process which often leads to failure of arterial bypass or hemodialysis access. Experimental and clinical work have provided insight in IH development; however, further studies under precise controlled conditions are required to improve therapeutic strategies to inhibit IH development. Ex vivo perfusion of human vessel segments under standardized hemodynamic conditions may provide an adequate experimental approach for this purpose. Therefore, chronically perfused venous segments were studied and compared to traditional static culture procedures with regard to functional and histomorphologic characteristics as well as gene expression. MATERIALS AND METHODS: Static vein culture allowing high tissue viability was performed as previously described. Ex vivo vein support system (EVVSS) was performed using a vein support system consisting of an incubator with a perfusion chamber and a pump. EVVSS allows vessel perfusion under continuous flow while maintaining controlled hemodynamic conditions. Each human saphenous vein was divided in two parts, one cultured in a Pyrex dish and the other part perfused in EVVSS for 14days. Testing of vasomotion, histomorphometry, expression of CD 31, Factor VIII, MIB 1, alpha-actin, and PAI-l were determined before and after 14days of either experimental conditions. RESULTS: Human venous segments cultured under traditional or perfused conditions exhibited similar IH after 14 days as shown by histomorphometry. Smooth-muscle cell (SMC) was preserved after chronic perfusion. Although integrity of both endothelial and smooth-muscle cells appears to be maintained in both culture conditions as confirmed by CD31, factor VIII, and alpha-actin expression, a few smooth-muscle cells in the media stained positive for factor VIII. Cell-proliferation marker MIB-1 was also detected in the two settings and PAI-1 mRNA expression and activity increased significantly after 14 days of culture and perfusion. CONCLUSION: This study demonstrates the feasibility to chronically perfuse human vessels under sterile conditions with preservation of cellular integrity and vascular contractility. To gain insights into the mechanisms leading to IH, it will now be possible to study vascular remodeling not only under static conditions but also in hemodynamic environment mimicking as closely as possible the flow conditions encountered in reconstructive vascular surgery.

Does Switzerland train tomorrow's surgeons today? Today's reflections on tomorrow's surgeons.

Various factors are influencing the Swiss health care system, and therefore, surgeons' actual and future profession. Initiated by the current president of the Swiss Society of Surgery, a group of eight young Swiss surgeons constituted the ad hoc committee "Chirurgie 2020". The goal was to develop several scenarios of the surgeon's professional situation in 20 years. The future direction of surgery will be markedly influenced by medical innovation, political and economic relationships between Switzerland and Europe. However, the development of health care costs represents the most powerful factor predicting all further changes. The current situation of today's surgeons is best characterised as "hamsters in the treadmill" who try to fulfill a multitude of diverging tasks causing major demotivation. In order to retain a leading role in the health care system, surgeons must take part in social and political activities. To provide an excellent curriculum, university and county hospitals must join together to form clinical and educational networks. A clearly defined and structured curriculum must be introduced by the Swiss Society of Surgery. From our current point of view, only everyone's strong personal commitment will help to find solutions and to improve the current and future situation. In particular, today's surgical residents must actively take part in the development of tomorrow's surgery.