Faculty Bibliography

There is a clear association between carotid artery stenosis and cognitive impairment. However, there is no consensus as to how to interpret this association, and what, if any, impact this connection should have on the management of carotid stenosis. A review of the relevant literature suggests that although an intervention to relieve carotid stenosis in patients without clinically significant cognitive impairment does not improve cognition, there may be a cognitive benefit with intervention for carotid stenosis in those patients with clinically significant cognitive disorders.

We report the case of a 55-year-old female who presented with symptomatic high-grade stenosis of the right internal carotid artery, years after her diagnosis of moyamoya disease (MMD), which had been treated with extensive carotid and cerebral vascular reconstructions. A percutaneous carotid revascularization was unsuccessful, and a carotid endarterectomy with bovine patch angioplasty was subsequently performed. The presence of symptomatic atherosclerotic carotid disease in combination with MMD, with all the perioperative challenges, has not been previously described.

Background Transfemoral aortic valve replacement (TAVR) is a novel technique for treating aortic stenosis, yet vascular complications are yet to be delineated. Objectives This study aims to study the vascular complications of TAVR with Edwards Sapien valves (Edwards Lifesciences Corp., Irvine, CA). Methods We performed a retrospective evaluation of TAVR patients. Standard demographics, femoral vessel and sheath size, access type (femoral cut-down [FC], percutaneous access [PFA], and iliac conduit [IC]), and treatment method were recorded. Complications were defined by the Valve Academic Research Consortium Criteria. Logistic regression was used for statistical analysis. Results A total of 99 patients underwent TAVR between February 15, 2012 and July 17, 2013 with an Edwards Sapien valve. Out of which, 48 were males with a mean age of 83 ± 7 years. Overall, 33 had FC, 58 had PFA, and 6 had an IC. A total of 17 major (2 aortic and 15 iliac) and 38 minor complications (36 access and 2 emboli) occurred. Aortic complications were managed by open repair (OR, 1) or percutaneous repair (PR, 1). Overall, 12 iliac injuries were managed by PR and 3 by OR. Out of the 33 groin complications in FC patients 8 (24%) were treated by OR, whereas 30 (52%) of the 58 groin complications in PTA patients were treated by PR. There were no differences in transfusion requirements or length of stay. Conclusion Vascular complications of TAVR are common with most being minor, related to access site and causing no immediate sequelae. Iliac injury can be managed by PR or OR. Aortic injury is associated with significant mortality. These findings increase vascular surgeons' awareness of these complications and how to manage them.

MAIN CONCLUSION/CONCLUSIONS:The activation and level of expression of an endogenous, stress-responsive biosensor (bioreporter) can be visualized in real-time and non-destructively using highly accessible equipment (fluorometer). Biosensor output can be linked to computer-controlled systems to enable feedback-based control of a greenhouse environment. Today's agriculture requires an ability to precisely and rapidly assess the physiological stress status of plants in order to optimize crop yield. Here we describe the implementation and utility of a detection system based on a simple fluorometer design for real-time, continuous, and non-destructive monitoring of a genetically engineered biosensor plant. We report the responses to heat stress of Arabidopsis thaliana plants expressing a Yellow Fluorescent Protein bioreporter under the control of the DREB2A temperature-sensing promoter. Use of this bioreporter provides the ability to identify transient and steady-state behavior of gene activation in response to stress, and serves as an interface for novel experimental protocols. Models identified through such experiments inform the development of computer-based feedback control systems for the greenhouse environment, based on in situ monitoring of mature plants. More broadly, the work here provides a basis for informing biologists and engineers about the kinetics of bioreporter constructs, and also about ways in which other fluorescent protein constructs could be integrated into automated control systems.

Tissue-engineered vascular grafts (TEVGs) are currently being developed to overcome the limitations and complications associated with traditional synthetic grafts. This article aims to review the current status of research into the production and use of tissue-engineered grafts. TEVGs have a number of theoretical advantages over synthetic grafts. The results of animal and human studies have been promising, but more work must be done before TEVGs can replace traditional grafts.

OJECTIVES/UNASSIGNED:The purpose of this study was to evaluate the outcomes of endoscopically harvested saphenous vein (EHSV) for lower extremity bypass (LEB) surgery. METHODS:Data from 91 consecutive patients who underwent LEB using EHSV between February 2003 and November 2012 were analyzed. Outcomes of interest were wound infection, patency, re-intervention and limb loss. RESULTS:Fifty-eight (64%) and 33 (36%) patients underwent femoropopliteal (FP) and femorotibial (FT) bypass using EHSV. Three (3%) patients had superficial and 1 (1%) deep wound infection. Primary and primary assisted patency at 5 years was 68% and 71% in the FP group and 56% and 65% in the FT group. Six (6%) patients underwent major amputation. No predicting factors for wound infection or graft patency were found. CONCLUSIONS:EHSV carries a low incidence of perioperative wound complication and has a reasonable mid-to-long-term patency regardless of the length of vein harvested.

Postoperative cerebral hyperperfusion syndrome (CHS) in patients undergoing carotid intervention is thought to be related to the absence of cerebral reserve. Although hyperperfusion syndrome is rare, severe postoperative headache is common and is considered to be a prodromal sign. Cerebral reserve is measured by studying the response of cerebral vessels to a vasodilator such as hypercarbia. We produced hypercarbia by holding respiration for 60 seconds during carotid endarterectomy. We attempted to evaluate the relationship between intraoperatively evaluated cerebral reserve and the development of postoperative headache which was severe enough to require the patient to take an over the counter analgesic (e.g., ibuprofen, acetaminophen, aspirin). Internal carotid artery flow 1 (F1), Pco 2, and blood pressure 1 (BP1) were recorded before and after (F2, Pco 2, and BP2) 60 seconds of apnea. An increase in flow of > 20% was considered indicative of adequate cerebral reserve. Patients were evaluated before discharge and with follow-up calls at 2 to 5 days postdischarge. Fisher exact test was used to evaluate categorical predictors. Unpaired t test was used to compare continuous variables. Results were considered significant when p < 0.05. A total of 30 nonconsecutive patients were evaluated prospectively. Of the 30 patients, 4 (Group I) developed severe postoperative headache; 26 did not (Group II). Demographics were similar in both the groups. Three patients in Group I and 16 patients in Group II had > 20% increase in flow (p = 0.6315). Pco 2 rose in both groups and BP2 was unchanged from BP1 in both groups. Lack of cerebral reserve does not appear to be related to the development of severe postoperative headache.