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.

Donor brain death inhibits tolerance induction in miniature swine recipients of fully MHC-disparate pulmonary allografts.

We have previously shown that a short course of high-dose tacrolimus induces long-term tolerance to fully mismatched lung allografts procured from healthy MHC-inbred miniature swine. Here, we investigate whether donor brain death affects tolerance induction. Four recipient swine were transplanted with fully mismatched lung grafts from donors that were rendered brain dead and mechanically ventilated for 4 h before procurement (Group 1). These recipients were compared to two control groups (Group 2: 4 h of donor ventilation without brain death [n = 5]; and Group 3: no donor brain death with <1 h of ventilation [n = 6]). All recipients were treated with a 12-day course of tacrolimus. In contrast to both groups of control animals, the swine transplanted with lung allografts from brain dead donors all rejected their grafts by postoperative day 45 and showed persistent responsiveness to donor antigen by MLR. Several additional swine underwent brain death induction and/or mechanical ventilation alone to determine the effects of these procedures on the expression of proinflammatory molecules. Significant increases in serum concentrations of IL-1, TNF-α and IL-10 were seen after brain death. Upregulation of IL-1 and IL-6 gene expression was also observed.

Minimally invasive surgery for thoracoabdominal aortic aneurysms.

Open surgical repair of thoracoabdominal aortic aneurysms (TAAA) remains a highly morbid procedure. In recent years, several minimally invasive techniques have been introduced to treat TAAA. These include hybrid procedures and purely endovascular approaches using modified aortic endografts. Although still investigational, this burgeoning technology has the potential to improve outcomes in TAAA repair, as well as to circumvent the morbidity and mortality associated with the traditional surgical approach to TAAA. While the reported experience is limited to several institutional case series, results are encouraging, and suggest that fenestrated and branched endografts are likely to figure prominently in the management of TAAA in the future. An overview of these minimally invasive techniques, as well as the role of computer-assisted imaging analysis, is provided.

The indirect alloresponse impairs the induction but not maintenance of tolerance to MHC class I-disparate allografts.

We studied the effects of indirect allorecognition on the induction and maintenance phases of tolerance in miniature swine cotransplanted with heart and kidney allografts. MHC class I-mismatched heart and kidney grafts were cotransplanted in recipients receiving CyA for 12 days. Recipients were unimmunized or immunized with a set of donor-derived or control third-party MHC class I peptides either 21 days prior to transplantation or over 100 days after transplantation. T-cell proliferation, delayed type hypersensitivity reaction (DTH) and antibody production were assessed. All animals injected with donor MHC class I peptides developed potent indirect alloresponses specific to the immunizing peptides. While untreated recipients developed stable tolerance, all animals preimmunized with donor allopeptides rejected kidney-heart transplants acutely. In contrast, when peptide immunization was delayed until over 100 days after kidney-heart transplantation, no effects were observed on graft function or in vitro measures of alloimmunity. Donor peptide immunization prevented tolerance when administered to recipients pre transplantation but did not abrogate tolerance when administered to long-term survivors post transplantation. This suggests that the presence of T cells activated via indirect allorecognition represent a barrier to the induction but not the maintenance of tolerance.

Phlegmasia cerulea dolens as a complication of percutaneous insertion of a vena caval filter.

Unsuccessfully treated iliofemoral venous thrombosis can result in pulmonary embolism, phlegmasia cerulea dolens, and post-thrombotic syndrome. Phlegmasia cerulea dolens is characterized by tense swelling of the lower extremity with tenderness of the thigh over the femoral vein, mottling of the limb, and absent distal pulses. Without treatment, phlegmasia cerulea dolens can progress to cause venous gangrene and ultimate limb loss. In the reported case, phlegmasia cerulea dolens developed in a middle-aged woman with metastatic thyroid carcinoma following Greenfield filter placement via the femoral vein after heparinization for deep-vein thrombophlebitis had failed.