Outcome After Open and Laparoscopic Aortic Surgery in Matched Cohorts Using Propensity Score Matching.

OBJECTIVE/BACKGROUND: To compare the post-operative and mid-term outcomes of laparoscopic aortic surgery with those of conventional aortic surgery performed by a surgical team trained in laparoscopic aortic surgery. METHODS: A prospective study was conducted between January 2006 and December 2011 with 228 consecutive patients having undergone aortic bypass surgery for either an abdominal aortic aneurysm (n = 139) or occlusive aorto-iliac disease (n = 89). Conventional open aortic surgery was carried out in 145 patients, and total laparoscopic repair in 83 patients. The composite primary end point measure grouped together the following adverse events (AEs): (1) any deaths < 30 days or later deaths related to the operation; (2) post-operative hemorrhage necessitating reoperation; (3) myocardial infarction ≤ 30 days; (4) stroke ≤ 30 days; (5) post-operative respiratory failure necessitating re-intubation or assisted ventilation ≥ 4 days; (6) aortic prosthesis infection; (7) aortic prosthesis occlusion; (8) any re-operation related to aortic surgery. In order to diminish bias attributable to the absence of randomization, the two surgical groups were matched by a propensity score enabling analysis of 50 pairs of patients having presented with identical pre-operative characteristics. Univariate analysis of the AE occurring during the first 30 post-operative days was followed by multivariate analysis through logistic regression. The rate of AE during follow up was calculated using the Kaplan-Meier method and the roles of the different co-variables were analyzed using the Cox model. RESULTS: Univariate analysis of the groups adjusted for propensity score showed that laparoscopic repair was associated with a significantly higher risk of AE over the first 30 post-operative days (p = .03). Logistic regression analysis showed that laparoscopic aortic technique (odds ratio [OR] 4.50; p = .01) and coronary artery disease (OR 4.67; p = .02) were independently related to the occurrence of an AE during the post-operative period. The occurrence of AEs during follow up was analyzed using the Cox model. Only two variables, laparoscopic aortic surgery (hazard ratio [HR] 4.40; p = .002) and coronary artery disease (HR 2.70, p = .02), were independently associated with the occurrence of an AE during follow up. The small number of patients included prevented a separate analysis with regard to aneurysmal and occlusive aortic disease. CONCLUSION: This study suggests that even with a well trained surgical team, the laparoscopic approach increases the risk for AEs observed in the course of aortic surgery. ClinicalTrials.gov Identifier: NCT02325700.

Laparoscopic surgery for coeliac artery compression syndrome: current management and technical aspects.

OBJECTIVES: The study aims to assess the feasibility and midterm outcome of trans-peritoneal laparoscopy for coeliac artery compression syndrome (CACS). DESIGN: Retrospective chart review involving four European vascular surgery departments and two surgical teams. MATERIALS AND METHODS: charts for patients who underwent laparoscopy for symptomatic CACS between December 2003 and November 2009 were reviewed. Preoperative computed tomography (CT) angiography and postoperative duplex scan and/or CT angiography were performed. RESULTS: Eleven consecutive patients (nine women) with a median age of 52 years (interquartile range: 42.5-59 years) underwent trans-peritoneal laparoscopy for CACS. All patients had a history of postprandial abdominal pain; weight loss exceeded 10% of the body mass in eight cases. Preoperative CT angiography revealed coeliac trunk stenosis >70% in all cases. One patient had additional aortitis and inferior mesenteric artery occlusion, while another patient presented with an occluded superior mesenteric artery. Two conversions occurred (one difficult dissection and one aorto-hepatic bypass needed for incomplete release of CACS). The median blood loss was 195 ml (range: 50-900 ml) and median operative time was 80 min (interquartile range: 65-162.5 years). Symptoms improved immediately in 10/11 patients (no residual stenosis) while one remained unchanged despite a residual stenosis treated by a percutaneous angioplasty. Symptoms reappeared in one patient due to coeliac axis occlusion. The mean follow-up period was 35 ± 23 months (range: 12-78 months). CONCLUSION: Our study demonstrates that trans-peritoneal laparoscopy for treating median arcuate ligament syndrome is safe and feasible. Additional patients and a longer follow-up are needed for long-term assessment of this laparoscopic technique.

Anti-thrombin therapy during warm ischemia and cold preservation prevents chronic kidney graft fibrosis in a DCD model.

Ischemia reperfusion injury (IRI) is pivotal for renal fibrosis development via peritubular capillaries injury. Coagulation represents a key mechanism involved in this process. Melagatran (M), a thrombin inhibitor, was evaluated in an autotransplanted kidney model, using Large White pigs. To mimic deceased after cardiac death donor conditions, kidneys underwent warm ischemia (WI) for 60 min before cold preservation for 24 h in University of Wisconsin solution. Treatment with M before WI and/or in the preservation solution drastically improved survival at 3 months, reduced renal dysfunction related to a critical reduction in interstitial fibrosis, measured by Sirius Red staining. Tissue analysis revealed reduced expression of transforming growth factor-beta (TGF-beta) and activation level of its effectors phospho-Smad3, Smad4 and connective tissue growth factor (CTGF) after M treatment. Fibrinolysis activation was also observed, evidenced by downregulation of PAI-1 protein and gene expression. In addition, M reduced S100A4 expression and vimentin staining, which are markers for epithelial mesenchymal transition, a major pathway to chronic kidney fibrosis. Finally, expression of oxidative stress markers Nox2 and iNOS was reduced. We conclude that inhibition of thrombin is an effective therapy against IRI that reduces chronic graft fibrosis, with a significantly positive effect on survival.

A novel p21-activated kinase binds the actin and microtubule networks and induces microtubule stabilization.

Coordination of the different cytoskeleton networks in the cell is of central importance for morphogenesis, organelle transport, and motility. The Rho family proteins are well characterized for their effects on the actin cytoskeleton, but increasing evidence indicates that they may also control microtubule (MT) dynamics. Here, we demonstrate that a novel Cdc42/Rac effector, X-p21-activated kinase (PAK)5, colocalizes and binds to both the actin and MT networks and that its subcellular localization is regulated during cell cycle progression. In transfected cells, X-PAK5 promotes the formation of stabilized MTs that are associated in bundles and interferes with MTs dynamics, slowing both the elongation and shrinkage rates and inducing long paused periods. X-PAK5 subcellular localization is regulated tightly, since coexpression with active Rac or Cdc42 induces its shuttling to actin-rich structures. Thus, X-PAK5 is a novel MT-associated protein that may communicate between the actin and MT networks during cellular responses to environmental conditions.

Prosthetic carotid bypass grafts for atherosclerotic lesions: a prospective study of 198 consecutive cases.

OBJECTIVES: Carotid endarterectomy (CEA) is the standard treatment for atherosclerotic lesions involving the carotid bifurcation. However, CEA can be challenging under some conditions. The goal of this study was to determine the outcome and durability of prosthetic carotid bypass grafting (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to CEA. METHODS: This is a prospective series of 198 consecutive patients with PCB, representing 12.4% of 1595 patients with a carotid reconstruction procedure performed in our department between September 1986 and December 2006. Qualifying event was stroke in 67 patients (34%) and transient ischaemic attack (TIA) in 45 (23%), and 86 patients (43%) were asymptomatic. Primary indications for PCB were extensive atherosclerotic lesions (n=71; 36%), carotid stenosis associated with kinking (n=49; 25%), recurrent stenosis (n=47; 23%), stenosis after radiation therapy (n=18; 9%) and technical failure of CEA (n=13; 7%), with excessive arterial wall thinning and perforation after endarterectomy (n=10) or intimal flap on completion digital angiography (n=3). RESULTS: The combined stroke and death rate at 30 days were 0.5% (one stroke). Median follow-up was 9.5 years (interquartile range (IQR): 6.2-18.3 years). At 10 years, primary patency was 97.9+/-3.4%. Six PCBs (3.0%) became occluded during follow-up; one patient had a restenosis greater than 50% and 18 patients (9.1%) had a restenosis of less than 50%. Five patients had an ipsilateral stroke (one postoperative stroke, one at 103 days with a patent PCB and three related to occlusion of the PCB at 4, 13 and 15 years after the procedure). At 10 years, cumulative stroke-free survival was 98.4+/-3.2%, and cumulative survival was 78.8+/-7.0%. CONCLUSIONS: PCB is a safe surgical alternative and is durable, with a low incidence of graft restenosis, when CEA seems hazardous.

[New treatments in vascular diseases]. / Nouveautés en chirurgie vasculaire.

In superficial venous insufficiency, surgery remains the treatment of choice. Endovenous therapies are a minimal invasive alternative, whose long-term results are not demonstrated yet. In the treatment of abdominal aortic aneurysm, endovascular repair (EVAR) and laparoscopic approach are comparatively studied with open repair, to define their precise indications. In occlusive arterial disease, endovascular treatment offers inferior results in term of durability and patency, however with a decrease in morbidity and mortality.

P21-activated kinase 4 (PAK4) is required for metaphase spindle positioning and anchoring.

The oncogenic kinase PAK4 was recently found to be involved in the regulation of the G1 phase and the G2/M transition of the cell cycle. We have also identified that PAK4 regulates Ran GTPase activity during mitosis. Here, we show that after entering mitosis, PAK4-depleted cells maintain a prolonged metaphase-like state. In these cells, chromosome congression to the metaphase plate occurs with normal kinetics but is followed by an extended period during which membrane blebbing and spindle rotation are observed. These bipolar PAK4-depleted metaphase-like spindles have a defective astral microtubule (MT) network and are not centered in the cell but are in close contact with the cell cortex. As the metaphase-like state persists, centrosome fragmentation occurs, chromosomes scatter from the metaphase plate and move toward the spindle poles with an active spindle assembly checkpoint, a phenotype that is reminiscent of cohesion fatigue. PAK4 also regulates the acto-myosin cytoskeleton and we report that PAK4 depletion results in the induction of cortical membrane blebbing during prometaphase arrest. However, we show that membrane blebs, which are strongly enriched in phospho-cofilin, are not responsible for the poor anchoring of the spindle. As PAK4 depletion interferes with the localization of components of the dynein/dynactin complexes at the kinetochores and on the astral MTs, we propose that loss of PAK4 could induce a change in the activities of motor proteins.

Evaluation of early regenerative processes in a preclinical pig model of acute kidney injury.

Renal failure due to ischemic injury is a common denominator of various clinical situations in critically ill patients. This study was designed to characterize the TPSO/Cholesterol synthesis and cell division pathways in response to different levels of ischemia. Porcine kidneys were subjected to either 60 min-warm ischemia (WI) or auto-transplanted after cold storage for 24 h at 4°C (CS), or both conditions (WI+CS), pathway activation and function were evaluated at 3 h, 3 and 7 days after reperfusion. CS combined to WI affects renal functions indicating a high degree of injury. During the first week of reperfusion, renal levels of free and esterified cholesterol, major cellular components, increased in CS group with an attenuated production when WI was associated. CS and WI+CS groups exhibited an elevated expression of cell cycle induction markers such as PCNA and stathmin. TSPO expression was highest in groups with the lowest injury, and correlated with kidney outcome, revealing its potential for diagnosis.

Total laparoscopic aortic repair for occlusive and aneurysmal disease: first 95 cases.

OBJECTIVES: To analyze the outcome of our preliminary experience with total laparoscopic aortic repair in patients with occlusive or aneurysmal disease. MATERIAL AND METHODS: From September 2002 to April 2005, we performed 95 consecutive total laparoscopic aortic repair procedures including 72 for aortic occlusive disease (group A) and 23 for abdominal aortic aneurysm (group B). RESULTS: In group A, mean operating time was 216+/-50 min with a mean clamp time of 57+/-21 min and surgical conversion was required in two cases (2.7%). No postoperative death occurred but there were three postoperative complications necessitating re-intervention (retroperitoneal hematoma, embolic ischemia, and early prosthetic infection). Mean duration of hospitalization was 8 days (range, 5-42 days). All grafts were patent at 2 months. In group B, mean operating time was 251+/-57 min with a mean clamp time of 101+/-15 min and surgical conversion was required in seven cases (30%). There was one postoperative death (4.3%) due to pulmonary embolism and one non-fatal complication (retroperitoneal hematoma). Mean duration of hospitalization was 6.4 days (range, 4-12 days). All grafts were patent at 2 months. CONCLUSION: Total laparoscopic repair is feasible and safe for occlusive and aneurysmal aortic disease. Operators must acquire technical skills using simulators.

Regulation of Xenopus p21-activated kinase (X-PAK2) by Cdc42 and maturation-promoting factor controls Xenopus oocyte maturation.

Signal transduction cascades involved in regulation of the cell cycle machinery are poorly understood. In the Xenopus oocyte model, meiotic maturation is triggered by MPF, a complex of p34(cdc2)-cyclin B, which is activated in response to a progesterone signal by largely unknown mechanisms. We have previously shown that the p21-activated kinase (PAK) family negatively regulates the MPF amplification loop. In this study, we identify the endogenous PAK2 as a key enzyme in this regulation and describe the pathways by which PAK2 is regulated. We show that the small GTPase Cdc42 is required for maintenance of active endogenous X-PAK2 in resting stage VI oocytes, whereas Rac1 is not involved in this regulation. During the process of maturation, X-PAK2 phosphorylation results in its inactivation and allows maturation to proceed to completion. Activation of mitogen-activated protein kinase and cyclin B-p34(cdc2) is coincident with X-PAK2 inactivation, and purified active MPF inhibits X-PAK2, demonstrating the existence of a new positive feedback loop. Our results confirm and extend the importance of p21-activated kinases in the control of the G(2)/M transition. We hypothesize that the X-PAK2/Cdc42 pathway could link p34(cdc2) activity to the major cytoskeleton rearrangements leading to spindle migration and anchorage to the animal pole cortex.