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T S Roberts

Publications and source records attributed to T S Roberts.

44 records · Page 3Linked to original sources
PubMed1975

Regional cerebral blood flow studies following superficial temporal-middle cerebral artery anastomosis.

Regional cerebral blood flow (rCBF) studies were performed during the postoperative period on 16 patients with internal carotid occlusions and inaccessible stenoses, and middle cerebral artery occlusion and stenoses, who underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses. The intra-arterial xenon method with selective application of the xenon bolus through the internal carotid and the newly established superficial temporal channel has allowed comparison of the flow provided by the pathological input with flow through the new input. The results show that initial rCBF (rCBF1) was globally reduced in all patients to a mean of 28.4 +/- 11.9 ml/100 gm/min at a mean pCO2 of 29.6 +/- 9.55 mm Hg. Patients with transient ischemic attacks (TIA) and minor strokes with minimal residua (RIND) had a mean rCBF1 of 30.4 +/- 11.6 ml/100 gm/min at a mean pCO2 of 30 +/- 10 mm Hg, while patients with completed strokes had a mean rCBF1 of 25.0 +/- 12.4 ml/100 gm/min at a mean pCO2 of 29.1 +/- 8.8 mm Hg. There was no significant difference between these two groups. This finding suggests that in this small group of patients with TIA's and RIND's, the cause of the stroke is probably related more to decreased perfusion than embolus, and may explain why these patients' symptoms improve after STA-MCA anastomosis. The results of this study suggest that in addition to an inaccessible lesion, global or focal decreased rCBF is a necessary criterion in the definition of indications for intracranial revascularization procedures.

Cerebral Angiography↗
PubMedDate not supplied

Anterior cruciate ligament reconstruction using freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts. Two year results in thirty-six patients.

Thirty-six of 44 patients (82%) who underwent ACL reconstruction using freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts were evaluated at least 2 years postoperatively. A detailed subjective evaluation using the Lysholm scale was recorded as well as a functional evaluation using the Tegner activity scale. All of the patients received a detailed physical examination that included testing with the KT-1000 ligament arthrometer and the Cybex dynamometer. Complete chart reviews and radiographic evaluations were also obtained. Only 17 patients were considered to be functionally successful and performing at their desired activity level. The average KT-1000 showed a side-to-side difference of 5.9 mm at 30 pounds for the successful group and 7.9 mm for those who had functional failure. The Lysholm scores were 91.6/100 versus 61.1/100 in the failures. Eight patients (22%) at repeat surgery were noted to have complete dissolution of the graft. Large femoral cysts were noted radiographically in all of these patients. It was concluded that freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts have a high failure rate and cannot be recommended for ACL reconstruction.

Adolescent↗
PubMedDate not supplied

Anterior cruciate ligament reconstruction using bone-patellar tendon-bone allografts. A biological and biomechanical evaluation in goats.

Twenty-eight goats underwent ACL reconstruction with freeze-dried bone-patellar tendon-bone allografts in one knee, the opposite knee serving as a control. One group of 16 knees was evaluated, in groups of four, at 6, 12, 26, and 52 weeks by histologic and vascular injection techniques. The other group of 12 knees was evaluated in two groups of six at 26 and 52 weeks by morphological and biomechanical techniques of analysis. Within the first 12 weeks these allografts were revascularized; in the first 26 weeks they had matured to resemble normal connective tissue. Graft stiffness was 29% of the control value and maximum force to failure was 43% of the control value. The results of this study indicated that freeze-dried bone-patellar tendon-bone allografts are biomechanically and biologically similar to patellar tendon autografts.

Animals↗
PubMedDate not supplied

Lack of CNS depression from large doses of trimethaphan in sheep.

It is not uncommon to observe prolonged CNS depression for several hours following controlled hypotension and halothane anesthesia for neurosurgery. The present study evaluates possible contribution of large doses of trimethaphan to CNS depression. Four adult sheep were placed on transapical left ventricular bypass (TALVB) withdrawing blood from the apex of the left ventricle through a roller pump, Pall Ultipor filter, and returning the blood to a carotid artery. In the awake and unanesthetized animals, 1 to 2 gm of trimethaphan were administered IV during each experiment while maintaining mean arterial pressure at 60 to 75 torr. Two sheep stood up and knelt down without obvious correlation with dose of trimethaphan administered at the time; two remained standing and continued eating during the trimethaphan infusion. Cardiovascular recovery from these large doses of trimethaphan was within 15 to 30 minutes after the conclusion of drug infusion. The data strongly suggest that large doses of trimethaphan have no significant CNS depression in the awake and unanesthetized sheep.

Animals↗