Lactate flux during carotid endarterectomy under general anesthesia: correlation with various point-of-care monitors.

PURPOSE: The ability to assess the brain-at-risk during carotid endarterectomy (CEA) under general anesthesia remains a major clinical problem. Point-of-care monitoring can potentially dictate changes to management intraoperatively. In this observational study, we examined the correlation between a series of point-of-care monitors and lactate flux during CEA. METHODS: Both neurosurgeons and vascular surgeons participated in the study. The patients underwent arterial-jugular venous blood sampling for oxygen, carbon dioxide, glucose, and lactate, n = 26; bispectral index (BIS) monitoring ipsilateral to side of surgery, n = 26; raw and processed electroencephalogram (EEG), n = 22; and bi-frontal cerebral oximetry using the Fore-Sight monitor, n = 20. RESULTS: One patient experienced a new neurological deficit when assessed at 24 hr following surgery. Lactate flux into the brain was correlated with the greatest decrease in cerebral oximetry with carotid cross-clamping; lactate efflux was correlated with the least. The most noticeable changes in processed EEG (density spectral analysis) were also seen with lactate influx, but at a slower time resolution than cerebral oximetry. Loss of autoregulatory behaviour was demonstrated with lactate influx; however, no correlation was seen between lactate flux and BIS monitoring. CONCLUSION: There was a correlation between cerebral oximetry and lactate flux during carotid cross-clamping. The Fore-Sight monitor may be of value as a point-of-care monitor during CEA under general anesthesia. A novel finding of this study is lactate flux into the brain in the presence of a large difference in cerebral oxygenation during cross-clamping of the carotid artery. Registered at clinicaltrials.gov: NCT000737334.

Determination of functional outcome following upper extremity arterial trauma.

Upper extremity arterial trauma may lead to significant disability with a poor functional outcome. This study represents a retrospective review of all trauma patients presenting to a university-affiliated medical center. Patients suffering from upper extremity arterial injuries requiring treatment were identified. The injured vessels were identified along with the mechanism of injury and method of repair. The degree of functional disability was evaluated by using a previously validated questionnaire, the Disabilities of the Arm, Shoulder, and Hand (DASH) Outcome Measure. Between September 1999 and December 2004, 17 patients presented with traumatic arterial injury to the upper extremity, with 9 and 8 patients suffering from blunt and penetrating traumas, respectively. One patient required amputation representing a limb salvage rate of 94%. The mean length of hospitalization was significantly shorter for penetrating trauma (5.1 vs 12 days, P = .03), with blunt trauma victims being more prone to coexisting orthopedic injuries (P = .009). Length of follow-up did not differ between the 2 groups and ranged from 1-60 months. Patients with blunt trauma tended, although not statistically significant, to have higher DASH scores (61.8 vs 22.8, P = .08), indicating a greater degree of disability. By utilizing a validated disability questionnaire, this study confirms that patients suffering from blunt injuries to upper extremity arteries are more likely to have greater degrees of disability affecting everyday activities.

Nineteen-millimeter prosthetic aortic valves allow normalization of left ventricular mass in elderly women.

BACKGROUND: Implantation of small aortic valve prostheses has been reported to be associated with impaired left ventricular (LV) mass regression and incomplete resolution of symptoms although these data have been generated largely with male patients. Therefore we sought to determine the clinical and hemodynamic outcomes of female patients who received a 19-mm aortic valve. METHODS: Between May 1995 and December 2000, 38 female patients (average age 73 years, range 42 to 89) underwent isolated aortic valve replacement (AVR; n = 22) or AVR plus coronary artery bypass graft surgery (CABG; n = 16) with a 19-mm aortic prosthesis. The average New York Heart Association (NYHA) class was 3.08 and of the 26 patients who had angina, 47.2% were in CCS class III or IV. Clinical and echocardiographic follow-up was done an average of 33.4 months (8 to 72) after surgery. RESULTS: Operative mortality was 10.5%. Overall survival at an average of 33 months was 71.1%. The average NYHA class was 1.52 +/- 0.34 postoperatively (p < 0.001 versus preoperative) and 95% had no anginal symptoms or were in Canadian Cardiovascular Society class I. The LV mass index showed significant regression (114 +/- 11 g/m2 to 89 +/- 9 g/m2, p = 0.001) despite an effective orifice area index (EOAI) of 0.64 +/- 0.09 cm2/m2. CONCLUSIONS: Despite a very small EOAI, elderly female patients with 19-mm prosthetic aortic valves can experience a satisfactory improvement in symptoms and normalization of LV mass. This finding suggests that small prosthetic aortic valves continue to have an application in contemporary cardiac surgical practice. The current perception of patient-prosthesis mismatch may need to be reconsidered for select populations.

Hybrid open and endovascular therapy for a proximal subclavian artery aneurysm.

A 57-year-old male presented with a large proximal right subclavian artery aneurysm that had been the source of upper extremity emboli on two occasions. A combined open and endovascular approach was undertaken involving a common carotid to vertebral artery autogenous bypass via a supraclavicular incision and endovascular repair of the aneurysm from a transbrachial approach. The patient did well postoperatively and recovered fully following a short hospitalization.

Ruptured mycotic abdominal aortic aneurysm secondary to Mycobacterium bovis after intravesical treatment with bacillus Calmette-Guérin.

Bacillus Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis that has proven effective in the treatment of early-stage bladder cancer. Although intravesical therapy with BCG is generally considered safe, serious complications including hematuria, granulomatous pneumonitis, hepatitis, and life-threatening BCG sepsis are well known. BCG-related vascular infections are rarely reported. We present a case of a ruptured abdominal aortic aneurysm secondary to M bovis infection 2 years after intravesical instillation of BCG and review the related literature.

Osteopontin localizes to the nucleus of 293 cells and associates with polo-like kinase-1.

Osteopontin (OPN) is a secreted phosphoprotein involved in cellular proliferation and associated with tumor progression. Although an intracellular form of OPN has been described, its function remains unknown. In this study, a novel nuclear location for intracellular OPN and a correlation with cell division were demonstrated. OPN distinctly localized to the nucleus in a subset of transiently transfected human embryonic kidney 293 cells. Immunoblotting confirmed the nuclear location of native OPN, and results from immunofluorescence studies suggested an association between nuclear OPN and cell cycle progression. Flow cytometry revealed that nuclear and cellular OPN content rose significantly during the S and G(2)/M phases, respectively. Treatment of cells with the DNA polymerase inhibitor aphidicolin prevented cell cycling and greatly reduced cellular OPN content. The intracellular location of OPN coincided with polo-like kinase-1 (Plk-1), a member of the polo-like kinase family, which, in part through their regulation of centrosome-related events, are integral to successful cellular mitosis. OPN and Plk-1 were coimmunoprecipitated from nuclear, but not cystoslic, extracts, demonstrating an interaction that is limited to the nucleus, presumably during mitosis. Deletion of the COOH terminus of OPN militated against nuclear localization and Plk-1 interaction. Elevated expression of OPN was also associated with an increase in the number of multinucleate 293 cells, whereas transfection of the COOH-terminal-deleted OPN decreased the percentage of multinucleate cells below basal levels. These findings implicate intranuclear OPN as a participant in the process of cell duplication.

Endovascular repair of Salmonella-infected abdominal aortic aneurysms: a word of caution.

Over the last several years, treatment modalities have changed for infected aortic aneurysms. Surgical treatment has undergone a paradigm shift from débridement and extra-anatomic bypass to direct reconstruction to, most recently, endovascular repair. Although many reports of endovascular repair of such aneurysms are favorable, the following two cases highlight some of the concerns with endografts in an infected field. Specifically, we urge caution when considering endovascular repair of Salmonella-infected arterial pathologies.

Comparison of renal function after endovascular aneurysm repair with different transrenally fixated endografts.

OBJECTIVE: Transrenal fixation of abdominal aortic endografts may provide a more secure proximal attachment with few deleterious effects with respect to renal function. This study's purpose was to determine whether different metals used in two commercially available endografts (Cook Zenith and Medtronic Talent) result in different effects on renal function when placed across renal ostia. METHODS: A total of 140 consecutive patients, between August 2003 and April 2005, who underwent elective endovascular repair of an aortic aneurysm with a nitinol or stainless steel-based endograft with transrenal fixation were reviewed with a mean follow-up period of 5.5 months (range, 1-22 months). The main outcome variable was the percentage change in creatinine clearance (CrCl), which was determined before surgery and at the most recent follow-up. Multiple regression analysis was performed to analyze the contribution of various factors to any deterioration in renal function. RESULTS: The 140 patients were predominantly male (86%), with a mean age of 75 years (range, 56-92) and a mean aneurysm diameter of 62 mm (range, 42-110 mm). The mean intraoperative contrast use was 67 mL (range, 45-160 mL), and after surgery these patients received a mean of 3 surveillance computed tomographic scans (range, 1-7). Nineteen cases (13.6%) required deliberate accessory renal artery coverage. CrCl did not change significantly after surgery; the mean change in CrCl at the end of follow-up was a 2.5% decrease. There was no difference in the reduction in CrCl between endograft types. Only 14.3% of patients experienced a greater than 20% decrease in CrCl. Multiple regression analysis failed to show a relationship between change in renal function and age, sex, aneurysm diameter, infrarenal neck dimensions, endograft type, coverage of accessory renal arteries, intraoperative contrast volume, preoperative CrCl, and postoperative computed tomographic scans. Length of follow-up was an independent predictor (P = .04). CONCLUSIONS: Transrenal endograft fixation results in little deterioration in renal function during intermediate follow-up. The few patients who do experience a decline in renal function do so independently of any features related to the initial endovascular repair, and there is no difference in renal deterioration between endografts with nitinol and stainless steel transrenal bare metal stents.