Comparison of outcomes after endovascular and open repair of abdominal aortic aneurysms in low-risk patients.

BACKGROUND: In randomized trials endovascular aortic aneurysm repair (EVAR) has been shown to have superior perioperative outcomes compared with open aneurysm repair (OAR). However, outcomes in patients at low risk of complications are unclear and many surgeons still prefer OAR in this cohort. The objective was to analyse perioperative and longer-term outcomes of OAR and EVAR in this low-risk group of patients. METHODS: All elective infrarenal EVARs and OARs in the Vascular Study Group of New England database were reviewed from 2003 to 2014. The Medicare scoring system was used to identity patients at low risk of perioperative complications and death. Perioperative and longer-term outcomes were analysed in this cohort. A Kaplan-Meier plot was constructed for evaluation of longer-term survival. Further propensity matching and multivariable analysis were performed to analyse additional differences between the two groups. RESULTS: Some 1070 patients who underwent EVAR and 476 who had OAR were identified. Mean(s.d.) age was 67·3(5·7) and 65·1(6·3) years respectively (P < 0·001). EVAR was associated with a lower overall perioperative complication rate (4·2 versus 26·5 per cent; P < 0·001). There was no difference in 30-day mortality (0·4 versus 0·6 per cent; P = 0·446). Overall survival at 3 years was similar after EVAR and OAR (92·5 versus 92·1 per cent respectively; P = 0·592). In multivariable analyses there was no difference in freedom from reintervention (odds ratio 1·69, 95 per cent c.i. 0·73 to 3·90; P = 0·220) or survival (hazard ratio 0·85, 0·61 to 1·20; P = 0·353). CONCLUSION: In patients predicted to be at low risk of perioperative death following aneurysm repair, EVAR resulted in fewer perioperative complications than OAR. However, perioperative mortality, reinterventions and survival rates in the longer term appeared similar between endovascular and open repair.

Rapid identification of Enterobacter hormaechei and Enterobacter cloacae genetic cluster III.

AIM: Enterobacter cloacae complex bacteria are of both clinical and environmental importance. Phenotypic methods are unable to distinguish between some of the species in this complex, which often renders their identification incomplete. The goal of this study was to develop molecular assays to identify Enterobacter hormaechei and Ent. cloacae genetic cluster III which are relatively frequently encountered in clinical material. METHODS AND RESULTS: The molecular assays developed in this study are qPCR technology based and served to identify both Ent. hormaechei and Ent. cloacae genetic cluster III. qPCR results were compared to hsp60 sequence analysis. Most clinical isolates were assigned to Ent. hormaechei subsp. steigerwaltii and Ent. cloacae genetic cluster III. The latter was proportionately more frequently isolated from bloodstream infections than from other material (P < 0·05). CONCLUSION: The qPCR assays detecting Ent. hormaechei and Ent. cloacae genetic cluster III demonstrated high sensitivity and specificity. SIGNIFICANCE AND IMPACT OF THE STUDY: The presented qPCR assays allow accurate and rapid identification of clinical isolates of the Ent. cloacae complex. The improved identifications obtained can specifically assist analysis of Ent. hormaechei and Ent. cloacae genetic cluster III in nosocomial outbreaks and can promote rapid environmental monitoring. An association was observed between Ent. cloacae cluster III and systemic infection that deserves further attention.

The evaluation of a novel technique to treat saphenous vein incompetence: preclinical animal study to examine safety and efficacy of a new vein occlusion device.

OBJECTIVES: We tested a novel technique to treat great saphenous vein (GSV) incompetence in an animal model. METHODS: V-block (VVT Medical Ltd, Kfar Saba, Israel), an occlusion device composed of a nitinol frame and anchoring hooks, was percutaneously deployed at the saphenofemoral junction in 12 sheep. Four of the 12 sheep were treated with adjunctive liquid sclerotherapy. Animals underwent duplex ultrasound, venography and histopathological evaluation immediately postimplantation at 30, 60 and 90 days. RESULTS: V-block was successfully deployed in all animals without adverse events. There was no device migration at follow-up. Histopathological analysis demonstrated V-block to be lodged within the GSV and surrounded by fibrous tissue in all samples. Obliteration of the GSV lumen, widespread intimal loss and multifocal medial smooth muscle loss was noted. CONCLUSIONS: In this animal study V-block was deployed without complications, remained in stable position and led to GSV occlusion. This device has promise for future use in humans.

Current state of affairs in the treatment of infrainguinal critical limb ischemia.

Atherosclerosis is widespread in Western society and is the leading cause of morbidity and mortality in the United States (US). Epidemiological studies indicate that peripheral artery disease (PAD) has a prevalence of 3-10% in the general population. This rate increases to 15-20% in persons over 70 years of age, and PAD is particularly common in individuals who smoke or have diabetes. Further highlighting the lack of current treatment uniformity, the Society for Vascular Surgery has recently designated the goal of clarifying optimal treatment for CLI as one of its top societal priorities.

The perspective of the vascular surgery trainee on new ACGME regulations, fatigue, resident training, and patient safety.

OBJECTIVE: To assess the opinions of vascular surgery trainees on the new Accreditation Council for Graduate Medical Education (ACGME) guidelines. METHODS: A questionnaire was developed and electronically distributed to trainee members of the Society for Vascular Surgery. RESULTS: Of 238 eligible vascular trainees, 38 (16%) participated. Respondents were predominantly 30 to 35 years of age (47%), male (69%), in 2-year fellowship (73%), and at large academic centers (61%). Trainees report occasionally working while fatigued (63%). Fellows were more likely to report for duty while fatigued (P = .012) than integrated vascular residents. Respondents thought further work-hour restrictions would not improve patient care or training (P < .05) and may not lead to more sleep or improved quality of life. Respondents reported that duty hours should vary by specialty (81%) and allow flexibility in the last years of training (P < .05). CONCLUSIONS: Vascular surgery trainees are concerned about further duty-hour restrictions on patient care, education, and training and fatigue mitigation has to be balanced against the need to adequately train vascular surgeons.

On spurious water flow during numerical simulation of steam injection into water-saturated soil.

Numerical simulation of steam injection into a water-saturated porous medium may be hindered by unphysical behavior causing the model to slow down. We show how spurious water flow may arise on the boundary between a steam zone and a saturated zone, giving rise to dramatic pressure drops. This is caused by the discretization of the temperature gradient coupled with the direct relation between pressure and temperature in the steam zone. The problem may be a severe limitation to numerical modeling. A solution is presented where the spurious water flow is blocked and this widely enhances the performance of the model. This new method is applied to a previously reported example exhibiting numerical problems. Furthermore, it is applied to the simulation of 2-D sandbox experiments where LNAPL is remediated from a smearing zone by steam injection. These experiments would have been difficult to analyze numerically without the adjustment to prevent spurious flow.

Cryopreserved saphenous vein allografts in infrainguinal arterial reconstruction.

Cryopreserved saphenous vein allografts (cryografts) have been used as conduit in infrainguinal revascularization when autogenous vein is inadequate or unavailable. Numerous reports on the subject exist, however most are hampered by small sample size or retrospective design. Despite poor patency rates, limb salvage in patients undergoing cryograft bypass is acceptable. In this article we review the literature of cryograft use in infrainguinal revascularization and define its role in the armamentarium of the modern vascular surgeon.

Interleukin regulation of asymmetric antibody synthesized by isolated placental B cells.

PROBLEM: Protecting antibodies against trophoblast surface molecules were previously described. Here we analysed the synthesis of asymmetric IgG by placental B-lymphocytes. METHOD OF STUDY: B cells were isolated from human term placenta and cord blood, stimulated with anti-CD40 IgG and cocultured with transfected Fcgamma R-expressing mice Ltk-fibroblast. Interleukin-4, IL-6, IL-10, IL-11 and IL-13 were added to cultures for 14 days. Asymmetric IgG were assessed in culture supernatants by concanavalin A (Con A) fixation and enzyme-linked immunosorbent assay. RESULTS: When IL-6 was added to the cultures, the percentages of asymmetric IgG synthesized by placental B cells were: IL-6: 29 +/- 10; IL-6 + IL-10: 24 +/- 7; IL-4 + IL-10 + IL-6: 38 +/- 9. The last combination induced the highest increase in the asymmetric IgG synthesis as compared with control (19 +/- 10%, P < 0.05). Additionally, placental B cells synthesized more asymmetric IgG than umbilical cord blood B-lymphocytes (P = 0.0015). CONCLUSIONS: Isolated placental B-lymphocytes synthesized asymmetric IgG in response to Th2 interleukins, more notably IL-6 in combination with IL-4 and IL-10. The in vitro increase of protective asymmetric IgG synthesis in response to Th2-cytokines support the hypothesis that a local Th2-switch is beneficial for pregnancy outcome.

Recovery of cardiac function after standard hypothermic storage versus preservation with Peg-hemoglobin.

Preservation of the heart for transplantation after infusion of cardioplegia and extirpation of a cardiac allograft results in an ischemic insult to the myocardium. This ischemic insult may lead to a loss of function in the transplanted heart. Hypothermic perfusion preservation with an oxygen hemoglobin carrying solution may avert ischemic injury and lead to improved recovery of cardiac function. The purpose of this study was to compare cardiac function after 8 hours of continuous hypothermic perfusion with a unique polyethylene-glycol-hemoglobin (PEG-Hb) solution to hearts preserved by 4 hours of hypothermic ischemic storage. Freshly extirpated hearts served as functional controls. The hearts of 26 anesthetized and intubated New Zealand white rabbits were harvested after cold cardioplegic arrest. Group I (n = 12) hearts were perfused with a PEG-Hb solution at 20 degrees C and 30 mm Hg for 8 hours. PO2 was maintained > or = 500 mm Hg. Group II (n = 7) hearts were preserved by cold ischemic storage for 4 hours at 4 degrees C. Group III (n = 7) were tested immediately after harvest. Left ventricular (LV) function was measured in the nonworking state at 15 minutes, 1 hour, and 2 hours after transfer to a standard crystalloid Langendorff circuit. Measurement of LV developed pressure, peak + dP/dt and -dP/dt revealed a superior trend between Group I and Group II hearts in comparison with freshly extirpated hearts. Heart rate was similar among all groups throughout testing (p = ns). Coronary blood flow was not significantly different between groups. Continuous perfusion preservation of rabbit hearts for 8 hours with PEG-Hb solution at 30 mm Hg and 20 degrees C yielded LV function that was similar to 4 hours of ischemic hypothermic storage. Furthermore, return of cardiac function after 8 hours of perfusion preservation using this PEG-Hb solution may be superior to that obtained in freshly extirpated hearts. These data suggest that some recovery of myocardial function may occur during perfusion preservation with this PEG-Hb solution after the ischemic insult of cardioplegic arrest. Continuous perfusion preservation using this PEG-Hb solution deserves further investigation in large animal transplant models.

Chronic antigen-specific immune-system activation may potentially be involved in the loosening of cemented acetabular components.

Previous studies have attempted to determine whether aseptic loosening and osteolysis are caused by a T cell-mediated type IV hypersensitivity reaction or a nonspecific foreign body reaction involving phagocytic macrophages. The purpose of this study was to examine the role of the B7-CD28 costimulatory pathway (which is indicative of an activated immune response) in loosening and osteolysis of total joint replacements (TJRs). We harvested periprosthetic tissues from 24 loose, cemented, all polyethylene, acetabular components in patients undergoing revision total hip replacement surgery for aseptic loosening. Prostheses were classified radiographically as to whether ballooning, scalloping osteolysis was present or not. Monoclonal antibodies were used to identify macrophages, antigen presenting cells (APCs) expressing B7-1 or B7-2, total T lymphocytes, and T cells expressing CD28 or CTLA-4. The large numbers of positive cells, including macrophages, T cells, and APCs in both groups are substantially higher than previously reported. Macrophages constituted the predominant cell type, the majority of which were APCs. B7-1 was expressed by 18.3% of all cells, and B7-2 was expressed by 61.0% of cells. Despite the fact that there were no statistically significant differences in expression of proteins in the B7-CD28 pathway between the osteolytic and nonosteolytic groups, the magnitude of positive staining suggests that the process of aseptic loosening (not osteolysis) may involve proteins of the B7-CD28 pathway, particularly B7-2. One possible antigenic stimulus is protein-coated particulate wear debris from prosthetic materials.

DIMA enlargement mammography in microcalcifications: a prospective study with ROC analysis.

The purpose of this study was to investigate whether the four-fold magnification mammography (direct magnification, DIMA) technique would perform better than conventional 1.5-fold magnification mammography in the differentiation of breast microcalcifications into benign and malignant. Fifty patients with non-palpable microcalcifications detected by mammography were examined immediately prior to surgical biopsy using both a conventional (1.5-fold) and the DIMA (fourfold) magnification mammography techniques. The microcalcifications were classified by five experienced radiologists using morphological criteria. A receiver operating characteristics curve (ROC) analysis of the sensitivity and specificity of both techniques in assessing malignancy was then carried out. The DIMA mammography technique was slightly but non-significantly superior to the conventional method in detecting malignancy (p > 0.05). Coarse granular and pleomorphic calcifications were detected more frequently with the DIMA technique. Coarse calcifications were significantly more frequently associated with histologically benign findings, whereas fine granular calcifications were significantly more likely to be malignant lesions. Assessment of malignancy associated with microcalcifications using morphological criteria is not significantly improved by mammography techniques with higher magnification.

Immunoglobulin heavy chain variable region gene replacement As a mechanism for receptor revision in rheumatoid arthritis synovial tissue B lymphocytes.

Mature B cells can alter their antibody repertoires by several mechanisms, including immunoglobulin heavy chain variable region (V(H)) replacement. This process changes the antigen combining site by replacing a portion of the original V(H)/diversity/heavy chain joining region (V(H)DJ(H)) rearrangement with a corresponding portion of a new V(H) segment. This exchange can involve cryptic heptamer-like sequences embedded in the coding regions of V(H) genes. While studying the B lymphocytes that expand in the synovial tissues of patients with rheumatoid arthritis (RA), clones with V(H)DJ(H) variants that were apparently generated by V(H) replacement were identified with surprising frequency (approximately 8%). Examples of multiple independent V(H) replacement events occurring in distinct progeny clones were also identified. These secondary V(H) rearrangements were documented at both the cDNA and genomic DNA levels and involved several heptamer-like sequences at four distinct locations within V(H) (three sites in framework region 3 and one in complementarity determining region 2). The identification of blunt-ended double-stranded DNA breaks at the embedded heptamers and the demonstration of recombinase activating gene (RAG) expression suggested that these rearrangements could occur in the synovial tissues, presumably in pseudo-germinal centers, and that they could be mediated by RAG in a recognition signal sequence-specific manner. The presence of V(H) mutations in the clones that had undergone replacement indicated that these B cells were immunocompetent and could receive and respond to diversification signals. A relationship between these secondary V(H) gene rearrangements and the autoimmunity characteristic of RA should be considered.

Matched-pair analysis of conventional versus endoluminal AAA treatment outcomes during the initial phase of an aortic endografting program.

PURPOSE: To investigate whether endovascular stent-grafts implanted during the early phase of an aortic endografting program have advantages over conventional surgical procedures for treatment of infrarenal aortic aneurysm (AAA). METHODS: In the first months of an endografting program, 37 patients (36 men; mean age 67.9 +/- 7.1 years, range 55 to 86) underwent AAA repair with endovascular implantation of a Vanguard (n = 17) or Talent (n = 20) bifurcated stent-graft. Data collected during the perioperative period and in follow-up were compared retrospectively to a matched group of 37 elective surgical patients. RESULTS: All endograft implantations were completed. Two type I and 6 type II endoleaks (21.6%) were seen postoperatively. Five type II sealed without intervention; 1 type I endoleak was corrected with an additional stent, but 1 type I and 1 type II endoleaks persisted despite attempts with coil embolization. Two (5.4%) endograft patients died during the perioperative period; however, this was not significantly different (p = 0.15) from the control group. In the mean follow-up of 12 +/- 6 months for both groups, 1 (2.7%) late conversion was necessary at 2 years for aneurysm expansion in an endograft patient with an unsealed type I endoleak. CONCLUSIONS: In our learning curve experience with aortic endografting, postoperative morbidity and mortality were higher in endograft patients compared to conventionally treated controls. Only in the endograft group was reoperation required during follow-up. Careful monitoring with periodic imaging studies is mandatory after endoluminal AAA treatment.

[Radiographic image magnification as quality control of microcalcification imaging within the scope of histopathological control of breast biopsy tissue]. / Vergrösserungspräparateradiographie als Qualitätskontrolle der Mikrokalkerfassung im Rahmen der histopathologischen Aufarbeitung von Mammabiopsiegewebe.

PURPOSE: Evaluation of specimen radiography as a quality control for the detection of microcalcifications by the pathologist during histopathological examination of breast biopsies. MATERIALS AND METHODS: 29 breast biopsy specimen with microcalcifications were radiographed using the magnification (x4) mammography System DIMA Plus MI I before and after the histopathological examination. Tissue with detected microcalcifications after the histopathological examination was reexamined histologically. RESULTS: In 55% (16/29) of all specimen we could identify missed microcalcifications. In 5 specimens the microcalcifications were missed completely. The radiologically detected areas of residual microcalcifications were reexamined histologically and in one case invasive parts of a carcinoma were detected, which primarily had been diagnosed as an in-situ carcinoma. In 6 cases the radiographs of the intraoperative specimen radiography were sent to the pathologist together with the biopsy. In these cases the rate of complete detection of the microcalcifications increased from 39% to 66%. CONCLUSION: Specimen radiography should be performed not only intraoperatively but also as part of the histopathological examination.

[Detection of microcalcifications in breast specimens by 4-fold DIMA direct magnification radiography compared to 1.5-fold conventional magnification radiography]. / Mikrokalknachweis in Mamma-Exzisionspräparaten mit Hilfe der DIMA-Vergrösserungspräparateradiographie vierfach im Vergleich zur konventionellen Vergrösserungsradiographie eineinhalbfach.

AIMS OF STUDY: The purpose of this study was to investigate the efficacy of 4-fold magnification breast specimen radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography in evaluating the presence or absence of carcinoma at the surgical margins by detection of microcalcification. METHODS: Fifty breast specimens with non-palpable microcalcifications were examined during surgical biopsy using both DIMA (4-fold) and conventional (1.5-fold) magnification specimen radiography. The number of detected microcalcifications of the whole specimen, of an area of 5 mm distance to the margins and of the area of the suspicious cluster of microcalcifications was counted and the results compared with the histological examination as a gold standard. RESULTS: In 50 specimen 2821 (1305 within 3 mm distance to the margins) microcalcifications were detected with the DIMA mammography technique compared to 1608 (446) microcalcifications with the conventional technique. This increased detection rate by DIMA-magnification radiography was accompanied by a decreased specificity in comparison to the conventional magnification radiography (33.3% DIMA versus 83.3% conventional) regarding the evaluation of presence or absence of carcinoma at the surgical margins. Differentiating the microcalcifications into calcifications belonging to the suspicious cluster and those that are located outside the cluster led to an increase in specificity (83.3% DIMA versus 100% conventional). CONCLUSIONS: The efficacy of breast specimen radiography in evaluating the presence or absence of carcinoma at the surgical margins by detection of microcalcification is not improved by 4-fold magnification radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography due to an increase in false-positive results. Analysis of the attachment of the microcalcifications to the cluster can improve the specificity.

[Digital subtraction angiography with carbon dioxide--basic principles, technique and clinical application]. / Digitale Subtraktionsangiographie mit Kohlendioxid--Grundlagen, Technik und klinische Anwendung.

Carbon dioxide digital subtraction angiography Carbon dioxide (CO2) digital subtraction angiography offers the possibility for diagnostic and interventional angiographic procedures in high risk patients for ionidated contrast material. As a gaseous contrast agent its physicochemical properties have special requirements concerning the radiologists knowledge, the X-ray equipment, the injector and the catheters. This article reviews the current literature concerning the history, physics and physiology, indications and contraindications, clinical use, adverse effects and possible complications of carbon dioxide digital subtraction angiography.