Systematic Review and Meta-analysis of Factors Influencing Survival Following Abdominal Aortic Aneurysm Repair.

BACKGROUND: Predicting long-term survival following repair is essential to clinical decision making when offering abdominal aortic aneurysm (AAA) treatment. A systematic review and a meta-analysis of pre-operative non-modifiable prognostic risk factors influencing patient survival following elective open AAA repair (OAR) and endovascular aneurysm repair (EVAR) was performed. METHODS: MEDLINE, Embase and Cochrane electronic databases were searched to identify all relevant articles reporting risk factors influencing long-term survival (≥1 year) following OAR and EVAR, published up to April 2015. Studies with <100 patients and those involving primarily ruptured AAA, complex repairs (supra celiac/renal clamp), and high risk patients were excluded. Primary risk factors were increasing age, sex, American Society of Anaesthesiologist (ASA) score, and comorbidities such as ischaemic heart disease (IHD), cardiac failure, hypertension, chronic obstructive pulmonary disease (COPD), renal impairment, cerebrovascular disease, peripheral vascular disease (PVD), and diabetes. Estimated risks were expressed as hazard ratio (HR). RESULTS: A total of 5,749 study titles/abstracts were retrieved and 304 studies were thought to be relevant. The systematic review included 51 articles and the meta-analysis 45. End stage renal disease and COPD requiring supplementary oxygen had the worst long-term survival, HR 3.15 (95% CI 2.45-4.04) and HR 3.05 (95% CI 1.93-4.80) respectively. An increase in age was associated with HR of 1.05 (95% CI 1.04-1.06) for every one year increase and females had a worse survival than men HR 1.15 (95% CI 1.07-1.27). An increase in ASA score and the presence of IHD, cardiac failure, hypertension, COPD, renal impairment, cerebrovascular disease, PVD, and diabetes were also factors associated with poor long-term survival. CONCLUSION: The result of this meta-analysis summarises and quantifies unmodifiable risk factors that influence late survival following AAA repair from the best available published evidence. The presence of these factors might assist in clinical decision making during discussion with patients regarding repair.

Late Radiological and Clinical Outcomes of Traumatic Thoracic Aortic Injury Managed with Thoracic Endovascular Aortic Repair.

PURPOSE: Patients treated with thoracic endovascular aortic repair (TEVAR) for traumatic thoracic aortic injury (TTAI) are often young and data on long-term durability of this treatment is not widely documented. The aims of this study were to report the New Zealand (NZ) national experience of TEVAR and to assess the durability of late outcomes and radiological follow-up of patients treated for TTAI. METHODS: Consecutive patients treated with TEVAR during a 12-year period from all tertiary centers in NZ were included. Early (30-day), late survival and radiological imaging data were recorded to document late graft-related complications and re-interventions. RESULTS: 88 patients with a median (range) age of 35 (15-87) year and 63 (71.6 %) males were included. Eleven patients (12.5 %) died within 30 days, of which three were aortic related deaths. The median (range) follow-up was 76.3 (0.3-164.6) months. Six (7.8 %) patients died during the follow-up period due to non-aortic-related causes. Nine (11.5 %) patients were lost to follow-up of which three emigrated overseas. Of those on surveillance, two patients required TEVAR re-intervention to previously treated aortic segments; one for a type 1b endoleak and the other for a symptomatic pseudo-coarctation. Both were treated successfully with a TEVAR. CONCLUSIONS: This multicenter study suggests that TEVAR is a durable option for treatment of traumatic thoracic aortic injury. Although, stent graft complications were uncommon, but when it occurred, it leads to re-intervention. Further radiological follow-up is required particularly in young patient to document late aortic/stent complications.

Prevalence of abdominal aortic aneurysm (AAA) in a population undergoing computed tomography colonography in Canterbury, New Zealand.

OBJECTIVE/BACKGROUND: There is compelling level 1 evidence in support of screening men for abdominal aortic aneurysm (AAA) to reduce AAA mortality. However, New Zealand (NZ) lacks data on AAA prevalence, and national screening has not been implemented. The aim of this study was to determine the prevalence of AAA in a population undergoing a computed tomography colonography (CTC) for gastrointestinal symptoms. METHODS: This was an observational study; all consecutive CTCs performed in three regions of the South Island of NZ over a 4 year period were reviewed. Data on abdominal and thoracic aorta diameters ≥30 mm, and iliac and femoral aneurysms ≥20 mm were recorded. Previous aortic surgical grafts or endovascular stents were also documented. Demographics, survival, and AAA related outcomes were collected and used for analysis. RESULTS: Included were 4,893 scans on 4,644 patients (1,933 men [41.6%], 2,711 women [58.4%]) with a median age of 69.3 years (range 17.0-97.0 years). There were 309 scans on 289 patients (75.4% men) who had either an aneurysm or a previous aortic graft with a median age of 79.6 years (range 57.0-96.0 years). Of these, 223 had a native AAA ≥30 mm. The prevalence of AAA rose with age from 1.3% in men aged 55-64 years, to 9.1% in 65-74 year olds, 16.8% in 75-84 year olds, and 22.0% in ≥85 year olds. The corresponding figures in women were 0.4%, 2%, 3.9%, and 6.2%, respectively. CONCLUSION: In this observational study, the prevalence of AAA was high and warrants further evaluation. The results acquired help to define a population that may benefit from a national AAA screening programme.

A nurse-run clinic for patients with incidentally discovered small abdominal aortic aneurysms is feasible and cost-effective.

INTRODUCTION: Patients with incidentally discovered small abdominal aortic aneurysms (AAA) require assessment by a vascular surgery department for possible enrollment in a surveillance programme. Our unit implemented a vascular nurse-run AAA clinic in October 2010. The aim of this study was to assess the feasibility of a specialist nurse-run small AAA clinic. METHODS: Demographic and clinical data were collected prospectively for all patients seen in the new vascular nurse clinic between October 2010 and November 2012. A validated AAA operative mortality score was used to aid decision making by the vascular nurse. RESULTS: Some 250 patients were seen in the clinic. 198 (79.2%) patients were enrolled in surveillance, 40 (16%) declined enrollment and 12 (4.8%) were referred to a consultant clinic for further assessment. The majority of patients were male and the mean age was 73.7 years. Co-morbidities included hypertension, a history of cardiovascular disease, and hyperlipidaemia. The majority of referrals were considered to be low operative risk. No aneurysms ruptured whilst under surveillance. CONCLUSIONS: A nurse-run clinic that assesses patients with incidentally discovered small AAAs for inclusion in AAA surveillance is a feasible alternative to assessment of these patients in a consultant-run clinic.

Spectral CT of carotid atherosclerotic plaque: comparison with histology.

OBJECTIVE: To distinguish components of vulnerable atherosclerotic plaque by imaging their energy response using spectral CT and comparing images with histology. METHODS: After spectroscopic calibration using phantoms of plaque surrogates, excised human carotid atherosclerotic plaques were imaged using MARS CT using a photon-processing detector with a silicon sensor layer and microfocus X-ray tube (50 kVp, 0.5 mA) at 38-µm voxel size. The plaques were imaged, sectioned and re-imaged using four threshold energies: 10, 16, 22 and 28 keV; then sequentially stained with modified Von Kossa, Perl's Prussian blue and Oil-Red O, and photographed. Relative Hounsfield units across the energies were entered into a linear algebraic material decomposition model to identify the unknown plaque components. RESULTS: Lipid, calcium, iron and water-like components of plaque have distinguishable energy responses to X-ray, visible on spectral CT images. CT images of the plaque surface correlated very well with histological photographs. Calcium deposits (>1,000 µm) in plaque are larger than iron deposits (<100 µm), but could not be distinguished from each other within the same voxel using the energy range available. CONCLUSIONS: Spectral CT displays energy information in image form at high spatial resolution, enhancing the intrinsic contrast of lipid, calcium and iron within atheroma. KEY POINTS: Spectral computed tomography offers new insights into tissue characterisation. Components of vulnerable atherosclerotic plaque are spectrally distinct with intrinsic contrast. Spectral CT of excised atherosclerotic plaques can display iron, calcium and lipid. Calcium deposits are larger than iron deposits in atheroma. Spectral CT may help in the non-invasive detection of vulnerable plaques.

Negative pressure wound therapy as an adjunct to compression for healing chronic venous ulcers.

OBJECTIVE: To determine the efficacy of negative pressure wound therapy (NPWT), when used in combination with compression bandaging, for healing chronic resistant venous ulcers. METHOD: In this pilot study, seven patients (with a total of 12 chronic resistant venous ulcers) received adjunctive NPWT and compression bandaging for 4 weeks. Their wounds were monitored for a total of 12 weeks. RESULTS: Dormant ulcers were seen to rapidly develop into healthy wounds, with a granulating base. CONCLUSION: This regimen may have a role in stimulating chronic venous ulcers into healing wounds, or in preparing them for skin grafting.

Dendritic cell loss from nonlymphoid tissues after systemic administration of lipopolysaccharide, tumor necrosis factor, and interleukin 1.

Dendritic cells (DC) in nonlymphoid organs can internalize and process foreign antigens before migrating to secondary lymphoid tissues to initiate primary immune responses. However, there is little information on which stimuli promote migration of DC from the tissues. Systemic administration of lipopolysaccharide (LPS), which induces in vivo production of cytokines, led to a reduction in the numbers of major histocompatibility complex class II-positive (Ia+) leukocytes in mouse hearts and kidneys: > 95% of DC were depleted 1-3 d after injection of 50 micrograms LPS. Several lines of evidence indicated that this response was due to migration of DC rather than loss of Ia expression or cytotoxic effects. In skin of treated mice, the number of Ia+ epidermal Langerhans' cells (LC) was reduced, and "cords" of Ia+ leukocytes became evident in the dermis. The latter cells expressed little NLDC145 and may have originated from recruited or resident DC progenitors. Systemic administration of recombinant tumor necrosis factor (rhTNF)-alpha resulted in a decrease in numbers of Ia+ cells in heart and kidney and of epidermal LC, and it also induced dermal cords. Administration of a rh-interleukin (IL)-1 resulted in a decrease in Ia+ cells only in renal medulla, appeared to activate a subset of epidermal LC, and induced dermal cords. Similar microgram doses of rhIL-2 had no obvious effect. Treatment with a neutralizing anti-TNF antiserum before LPS administration inhibited the depletion of LC from skin but not from heart or kidney. Therefore, TNF-alpha and IL-1 alpha may promote DC migration from nonlymphoid tissues and may have differential effects on different DC populations, but it is unclear whether they act on DC directly or indirectly (e.g., via other cytokines).

Effect of TNP on the microbiology of venous leg ulcers: a pilot study.

OBJECTIVE: To investigate the effect of topical negative pressure, delivered using Vacuum Assisted Closure (VAC, KCI), on the microbiology of chronic, non-infected venous leg ulcers (VLUs). METHOD: Patients receiving compression therapy for a chronic VLU were recruited into this prospective pilot study. The ulcer was swabbed and VAC was applied at 125mmHg continuous sub-atmospheric pressure on day 1 for six days. Standard methods for bacteriological sampling and measuring the wound surface area were applied at baseline and at the VAC dressing changes on days 3 and 6. Log median colony forming units (CFUs) per cm2 were used for statistical analyses. The bacterial species were identified. RESULTS: Seven patients were recruited into and completed the study. The median log10 CFU/cm2 on days 1, 3 and 6 were 3.5, 4.7 and 5.1 respectively. There was a significant increase in bacterial colonisation between days 1 and 6 (p<0.02). No change was observed in the identified microbiological species during therapy with VAC. CONCLUSION: This pilot study suggests that VAC therapy increases absolute numbers of bacteria colonising non-infected leg ulcers. DECLARATION OF INTEREST: KCI supplied the VAC equipment and ARANZ the SilhouetteMobile, but both had no other influence on the study.

Preemptive cadaveric renal transplantation--clinical outcome.

Preemptive cadaveric renal transplantation (PCRT) maximizes the chance of maintaining high quality of life and may avoid the morbidity of dialysis and the associated financial costs. These benefits are offset by disadvantages, which include the possibility of transplantation many months before the need for dialysis, resulting in wasted organ function; an immediate risk of graft failure with conversion to a dialysis-dependent state; and uncertainty of the safety of PCRT. Patients who underwent PCRT between June 1976 and December 1994 at the Oxford Transplant Centre were compared with a matched cohort of first cadaveric transplant recipients who were dialysis-dependent when transplanted. The 116 patients in the PCRT cohort were well matched to the control group with respect to sex, age, blood group, HLA match, degree of sensitization, donor age, immunosuppression, and year of transplantation. Patient and graft survival were significantly better in the PCRT group. The difference in graft survival did not appear to be completely explained by better patient survival, as suggested by a trend toward better graft survival after excluding death with a functioning graft as a cause of failure. Among surviving grafts there were no significant differences in graft function as assessed by 1, 2, and 3 year plasma creatinine levels. In conclusion, PCRT appears to be safe and may even be associated with superior graft survival when compared with conventional transplantation. Early inclusion on a transplant waiting list with a view to PCRT can be justified with respect to the clinical outcome but the financial costs and implications for the utilization of cadaveric donor kidneys must also be considered.

Late reflush in clinical renal transplantation. Protection against delayed graft function not observed.

Mechanical flushing of cadaveric kidneys with organ preservation fluid immediately before transplantation has been reported to be associated with improved early graft function. We report here the results of a prospective randomized controlled study of cadaveric renal transplantation after late reflush with organ preservation fluid in which no benefit with respect to delayed graft function was observed and, indeed, the protocol may have been harmful. The study was terminated after recruitment of only 18 patients (9 to each arm) because postreperfusion biopsies of reflushed kidneys contained unusual features, including abnormal cellular debris within the tubules or eosinophilic proteinaceous material within Bowman's capsule. These features were not present in the control kidneys. Acute tubular necrosis and biopsy-proven acute rejection episodes were more frequently seen in the reflushed kidneys, but at 1 year there was no significant difference in the function of the surviving grafts.

Systemic lipopolysaccharide recruits dendritic cell progenitors to nonlymphoid tissues.

Dendritic cells (DC) are thought to be the "passenger leukocytes" that sensitize the recipients of organ transplants against graft antigens and trigger allograft rejection. DC originate from MHC class II-negative (Ia-) progenitors in the bone marrow, which enter the tissues and develop into migratory cells with the specialized capacity to initiate primary immune responses. There is little information on which stimuli recruit DC progenitors to the tissues. Systemic administration of LPS to mice depletes Ia+ leukocytes from heart and kidney but recruits Ia- leukocytes (Roake JA, et al., see footnote 6). When these leukocytes were isolated and cultured overnight, Ia+ low density leukocytes developed that could stimulate primary T cell responses in vitro. Hearts from LPS-treated mice were transplanted to allogeneic recipients. One to 4 days after grafting, Ia+ donor cells were present in recipient spleens, localized to peripheral white pulp, and associated with CD4+, but not CD8+, T cells. Cells with the migratory characteristics of DC, therefore, originated from Ia- progenitors in the transplanted hearts. We conclude that LPS recruits Ia- DC precursors to the heart and kidneys. Hearts from LPS-treated donors were rejected by allogeneic recipients at the same tempo as normal hearts, implying that Ia- DC progenitors might ultimately contribute to heart graft rejection (direct sensitization). However, since hearts from cyclophosphamide-treated donors, which do not give rise to Ia+ cells in recipient spleens, were also rejected at a similar tempo, indirect sensitization could also play a role in heart graft rejection in this model.

Effect of one-HLA-haplotype-matched and HLA-mismatched blood transfusions on recipient T lymphocyte allorepertoires.

BACKGROUND: Pretransplant blood transfusion has a well-known beneficial effect on posttransplant graft survival. Recently, it has been proposed that the clinical benefit of transfusion is due to HLA-DR antigen sharing between the blood donor(s) and the recipient. Immunological studies have suggested that this might result from a functional deletion of donor-reactive cytotoxic T lymphocytes. METHODS: We investigated frequencies of alloreactive lymphocyte precursors with cytotoxic or interleukin-2-producing helper function by limiting dilution analysis in 10 renal dialysis patients before and after transfusion with fresh, allogeneic whole blood. Five patients received blood transfusions from donors matched for one HLA haplotype (or one HLA-B-DR antigen) and the other five patients received blood from fully HLA-mismatched donors. RESULTS: Contrary to some previous reports, frequency analysis of cytotoxic T lymphocyte precursors revealed no significant differences between the two treatment groups in terms of development of blood donor-specific hyporesponsiveness after transfusion. Split-well analysis of cytotoxic T lymphocyte precursors reactive with single-mismatched HLA antigens demonstrated that the effects of transfusion on alloreactive specificity are complex and may vary depending on the particular antigens mismatched between the recipient and blood donor. Analysis of donor-specific helper T lymphocyte precursor frequencies revealed a significant decrease of interleukin-2-producing cells 3 months after transfusion in the total patient population. This effect was most prominent in the recipients of HLA-mismatched blood, but it also exhibited some degree of nonspecificity, as frequencies of third-party reactive helper T lymphocyte precursors were also significantly reduced. CONCLUSIONS: Our overall results suggest that the degree of HLA matching between blood donor and recipient does not greatly influence the effect of blood transfusion on the T lymphocyte allorepertoire. The apparent induced down-regulation of helper T lymphocyte activity may play a role in the reported immunosuppressive effects of allogeneic blood transfusion.

Isolation of dendritic leukocytes from non-lymphoid organs.

These observation suggest that dendritic leukocytes from several different non-lymphoid organs in situ are functionally immature and that in this respect they more closely resemble epidermal LC than mature lymphoid DC. The exception appears to be the interstitial dendritic leukocytes from small and large intestinal lamina propria and Peyer's patches, where functional maturation could be attributed to constitutively secreted GM-CSF by lamina propria cell in situ, or alternatively to the isolation procedure which might lead to functional maturation of gut DC. After overnight culture, and possibly following organ transplantation, interstitial dendritic leukocytes may mature into potent activators of antigen-specific T-cell proliferation (immunostimulation). Further studies are needed to characterize dendritic leukocytes in solid non-lymphoid organs, and these may lead to new strategies for overcoming graft rejection by inhibiting the maturation of dendritic leukocytes after transplantation.

Acute appendicitis: a quality assurance analysis.

The management of 722 patients admitted to Christchurch Hospital in 1979 with acute appendicitis (308) or non-specific abdominal pain (414) was such that 86% of the appendicitis patients had a timely removal of an inflamed but not perforated appendix and 9.2% of the patients with non-specific abdominal pain had an unnecessary appendicectomy. The mean stay in hospital was 4.8 days for patients who had a timely operation for acute appendicitis, 8.1 days for patients undergoing operation for perforated appendicitis, 6.1 days for patients who had non-specific abdominal pain and appendicectomy, and 2.7 days for patients who had non-specific abdominal pain without appendicectomy. There was no mortality.

Cadaver kidney retrieval for transplantation in Canterbury and Westland: 1972-1987.

In Canterbury and Westland, 106 cadaver kidney donors have provided 186 kidneys, which have been transplanted or submitted for transplantation. The overall rate of 16 donor/million population/year, since 1973, is high by international standards [1,2]. Male donors (68%) had a median age of 20 years, and females a median age of 24 years. Motor vehicle accidents were responsible for 58% of deaths, followed by subarachnoid haemorrhage (15%). Cadaver nephrectomy was performed outside normal working hours in 58% of cases. Overall, 10% of kidneys removed were discarded, but none have been discarded since September 1980. Anatomical anomalies were common (42%).