J Cardiovasc Surg
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Paraplegia secondary to spinal cord ischemia is a too frequent devastating complication of thoracic aneurysm surgery. We examined the ability of veno-arterial bypass (VAB) to ensure adequate spinal cord blood flow during aortic cross-clamping by monitoring spinal cord function via somatosensory evoked potentials (SEP's) and postoperative motor function. Dogs were placed on VAB using a heparin-bonded roller pump circuit without systemic heparinization. ⋯ There were several transient hypotensive episodes (less than 5 min) which were accompanied by reversible loss of SEP's. None of the animals displayed any gait abnormalities post-op. These findings using this simple bypass technique suggest the following conclusions: (1) SEP's degenerate (increased latency and decreased amplitude) in response to hypoxia; (2) spinal cord function can be maintained for up to one hour during hypoxic conditions; (3) SEP's can be used to monitor sensory spinal cord function under these conditions; and (4) heparinless VAB can provide spinal cord protection while also allowing monitoring of SEP's to ensure adequate spinal cord perfusion.
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The results of operative lumbar sympathectomy for both intermittent claudication and rest pain in 153 patients have been reviewed. Sympathectomy was performed as an initial procedure to further below the groin reconstructive surgery, should symptoms not be alleviated. ⋯ The results in diabetics were not significantly different from those in non-diabetics. The possible value of lumbar sympathectomy in both claudication and rest pain is reviewed and discussed.
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Randomized Controlled Trial Comparative Study Clinical Trial
PTFE versus human umbilical vein in above knee femoro-popliteal bypass. Early results of a randomized clinical trial.
The results of a prospective randomized clinical trial comparing PTFE and HUV grafts in above knee femoro-popliteal reconstruction are presented. A total of 93 limbs were randomized, three patients died in the early postoperative period, leaving 90 (45 PTFE and 45 HUV bypasses) to be analysed. ⋯ From one year postoperatively onwards these results are statistically and significantly different. When an above knee femoro-popliteal reconstruction is performed and autologous vein is not available or purposely not used, HUV gives better results than PTFE and is the graft of choice.
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Comparative Study
Clear prime for infant cardiopulmonary bypass: a miniaturized circuit.
The extracorporeal circuit used clinically to perform cardiopulmonary bypass (CPB) in small infants is relatively large requiring blood to prime the circuit to reduce hemodilution. To study the merits of clear prime also in infants, we did experiments in rabbits with two extracorporeal circuits: one employing traditional venous gravity drainage (priming volume 330 ml) and the other employing vacuum drainage (priming volume 90 ml). ⋯ We demonstrated that the clear priming solution in the second circuit eliminates the hemodynamic deterioration caused by blood prime in the first circuit. Studying the effect of various modes of regulation, we showed that automatic control of CPB based on venous return is similar to autoregulation of the heart according to Starling's law, and maintains not only normal hemodynamics, but also an optimal microcirculation.
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In over 3500 consecutive open heart procedures using Swan-Ganz catheterization at our institution, we have experienced three major pulmonary artery injuries secondary to this procedure. Pulmonary artery hemorrhage is a rare but frequently fatal complication and a mortality rate as high as fifty percent has been reported. In two of these cases, major retraction of the heart was needed for adequate exposure of the cardiac pathology. ⋯ The authors have recommended steps to be taken when massive hemoptysis occurs and Swan-Ganz catheter perforation of the pulmonary artery is suspected. Re-evaluation of the "routine" use of the Swan-Ganz catheter may be necessary and overutilization may be a distinct possibility. When the use of this catheter is deemed appropriate, a more exact positioning of the distal portion of the catheter is mandatory if pulmonary artery perforation is to be avoided.