A new nonocclusive laser-assisted coronary anastomotic connector in a rabbit model

ObjectiveThe Excimer laser-assisted nonocclusive anastomotic technique is a nonocclusive, facilitated bypass technique that is currently Conformité Européenne and Food and Drug Administration approved for clinical application in neurosurgery. In the present study, we assessed the safety and feasibility of a newly developed Excimer laser-assisted nonocclusive anastomosis-based prototype coronary anastomotic connector in an acute rabbit abdominal aortic bypass model before application in experimental coronary bypass surgery. In addition, 2 sealants were tested to facilitate anastomotic hemostasis in the current device prototype.MethodsA total of 40 anastomoses were constructed on the abdominal aorta (3.5 mm outer diameter) of 10 rabbits. The anastomotic circumference was sealed by a surgical sealant to obtain complete hemostasis (BioGlue vs TachoSil). The anastomoses were evaluated by flow measurements construction time, hemostasis, histologic analysis, and burst pressure testing.ResultsThe connector enabled a nonocclusive and fast (6.0 ± 1.7 minutes, mean ± SD [including sealing]) anastomosis construction and complete hemostasis in 95% (35/37). Sealing with BioGlue was faster than with TachoSil (19% vs 53% of construction time). Despite technical imperfections (7/40 failures to completely retrieve the flap by the laser), all 40 anastomoses were patent, showed reproducible construction with intima–adventitia apposition, streamlining thrombus coverage of the intraluminal laser rim, and no vessel wall damage. All anastomoses resisted ex vivo supraphysiologic pressures (> 300 mm Hg).ConclusionsThe results of the present study have demonstrated that the Excimer laser-assisted nonocclusive anastomotic connector is safe and reliable and can be efficiently applied in an acute rabbit abdominal aortic bypass model. Provided the limitations can be addressed, this easy-to-use and nonocclusive technique has the potential to facilitate minimally invasive coronary bypass surgery

Hypomagnesemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE: Hypomagnesemia frequently occurs in hospitalized patients, and it is associated with poor outcome. We assessed the frequency and time distribution of hypomagnesemia after aneurysmal subarachnoid hemorrhage (SAH) and its relationship to the severity of SAH, delayed cerebral ischemia (DCI), and outcome after 3 months. METHODS: Serum magnesium was measured in 107 consecutive patients admitted within 48 hours after SAH. Hypomagnesemia (serum magnesium <0.70 mmol/L) at admission was related to clinical and initial computed tomographic characteristics by means of the Mann-Whitney U test. Hypomagnesemia at admission and during the DCI onset period (Days 2-12) was related to the occurrence of DCI and hypomagnesemia at admission, and hypomagnesemia that occurred any time during the first 3 weeks after SAH was related to outcome. RESULTS: Hypomagnesemia at admission was found in 41 patients (38%) and was associated with more cisternal (P = 0.006) and ventricular (P = 0.005) blood, a longer duration of unconsciousness (P = 0.007), and a worse World Federation of Neurosurgical Societies scale score at admission (P = 0.001). The crude hazard ratio for DCI with hypomagnesemia at admission was 2.4 (95% confidence interval, 1.0-5.6), and after multivariate adjustment it was 1.9 (95% confidence interval, 0.7-4.7). The hazard ratio of hypomagnesemia from Days 2 to 12 for patients with DCI was 3.2 (range, 1.1-8.9) after multivariate adjustment. The crude odds ratio for poor outcome (Glasgow Outcome Scale score, 1-3) with hypomagnesemia at admission was 2.5 (range, 1.1-5.5). Hypomagnesemia at admission did not contribute to the prediction of outcome in the multivariate model. CONCLUSION: Hypomagnesemia is frequently present after SAH and is associated with severity of SAH. Hypomagnesemia occurring between Days 2 and 12 after SAH predicts DCI

Frontal lobe damage and thalamic volume changes

The aim of this study was to investigate whether frontal lobe damage affects thalamic volume in humans. Ipsilateral and contralateral thalamic areas were measured in 0.5T T1-weighted sagittal magnetic resonance images in 12 patients, first at the time of their surgery for relief of a unilateral frontal lobe brain tumor and at follow-up ~2 years later. A 5% decrease in ipsilateral and 4.5% increase in contralateral thalamic area was found over time (F(I,II) = 6.15, p<0.05). We conclude that unilateral frontal lobe damage results in a decrease in the ipsilateral thalamus and an increase in the contralateral thalamus in humans in vivo. The findings may have implications for the interpretation of the reported changes in thalamic volume in neuropsychiatric diseases. (C) 2000 Lippincott Williams and Wilkins