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Biomedical subjects

I L Gordon

Publications and source records attributed to I L Gordon.

At least 37 records · Page 2Linked to original sources
PubMed1995

Definitive proof of endothelialization of a Dacron arterial prosthesis in a human being.

A 10 mm woven Dacron axillofemoral bypass graft was removed from a 65-year-old patient during redo surgery after an implant period of 26 months, because of a large seroma that surrounded the entire length of the graft. Tissue blocks were taken from representative areas along the entire length of the graft surface and evaluated by light microscopy with hematoxylin and eosin and Masson trichrome staining, scanning electron microscopy, transmission electron microscopy, and immunocytochemical staining. Paraffin-embedded sections were stained with smooth muscle cell alpha-actin, which demonstrated smooth muscle cells in the pseudointima, and Ham 56 stain to identify macrophages. Endothelial factor VIII/von Willebrand factor and Ulex europaeus agglutinin identified human endothelial cells on the flow surface, in areas far removed from the anastomoses to the native vessels. This is the first definitive proof in a human of endothelialization of a synthetic arterial graft beyond the pannus ingrowth zone.

Aged↗
PubMed1995

Redistribution of blood flow after carotid endarterectomy.

PURPOSE: We wanted to characterize the immediate effect of endarterectomy on flow of the arteries composing the extracranial carotid artery system. METHODS: Transit time ultrasound probes were used to measure flow through the carotid bifurcation in 48 patients undergoing endarterectomy. Maximum single-diameter stenosis affecting the internal carotid artery (ICA) was determined by angiography. The significance of differences between means were determined by t tests and analysis of variance; linear and nonparametric correlation analyses were also applied to analyze the relation between stenosis and several flow-derived parameters. RESULTS: Common carotid artery flow significantly increased (p = 0.0043) from a mean value of 264 +/- 99 ml/min to 314 +/- 98 ml/min, corresponding to an average percent increase of 34.3% +/- 71.3%. ICA flow increased from 128 +/- 69 ml/min to 173 +/- 66 ml/min (p < 0.0001), with an average percent increase of 74.9% +/- 114.9%. External carotid artery (ECA) flow decreased from 129 +/- 61 ml/min to 106 +/- 49 ml/min (p = 0.0098), representing an average percent decrease of -5.2% +/- 48.2%. The difference between ECA and ICA mean flow changes is highly significant (p < 0.001). The percent change in ECA flow did not correlate with preoperative stenosis. We noted, however, a positive correlation between stenosis and the ECA/ICA flow ratio before endarterectomy (Spearman r = 0.31, p = 0.032), indicating that more severe stenosis led to a greater distribution of blood into the ECA. The ECA/ICA flow ratio fell from an initial value (ECFbef/ICFbef) of 1.52 +/- 1.74 before endarterectomy to 0.69 +/- 0.37 (ECFaft/ICFaft) after endarterectomy (p = 0.0006). CONCLUSIONS: The data are consistent, with the ECA being an important collateral path for cerebral perfusion when ICA stenosis exists. When endarterectomy relieves bifurcation stenosis, common carotid artery blood flow is redistributed preferentially to the ICA at the expense of ECA flow, consistent with a change in the relative resistances of the two vessels resulting from operative reconstruction.

Blood Flow Velocity↗
PubMed1995

Inguinal wound fluid collections after vascular surgery: management by early reoperation.

Inguinal wounds complicated by significant fluid collections after vascular grafting procedures were managed by exploration soon after recognition in 14 patients. Within 24 hours, incisions were reexplored, fluid collections were evacuated and cultured, and closed suction drains were placed. The wound was reapproximated, and broad spectrum antibiotics were given intravenously until 24 hours after removal of the drain. Variables evaluated included spontaneous drainage before exploration, positive intraoperative wound cultures, exposure of graft when the wound was opened, and type of graft used. On careful follow-up, from 5 months to 3.5 years, averaging 14 months, only one patient had an infected graft, occurring 6 months after the wound exploration. There were no complications in wound healing from the inguinal explorations. These results suggest that early exploration and reclosure of clinically significant postoperative fluid collections is safe, results in primary healing, and has a low rate of subsequent graft infection.

Aged↗
PubMed1994

Intraoperative measurement of Javid shunt flow with transit-time ultrasound.

Transit-time ultrasound methods were used to measure blood flow in 37 patients undergoing carotid endarterectomy. Internal carotid flow before (ICFbef) and after (ICFaft) endarterectomy was measured with a 6 mm perivascular probe, and Javid shunt flow (SF) was measured with a clamp-on probe. For the entire group ICFbef averaged 117 +/- 67 ml/min and ICFaft was 173 +/- 67 ml/min. Shunt flow averaged 123 +/- 51 ml/min. The differences between ICFbef and ICFaft and between SF and ICFaft were significant (ANOVA, p < 0.01) but the difference between ICFbef and SF was not. The relationship between ICFbef and SF appeared to define two groups of patients. Those in whom SF was greater than ICFbef (SF > ICFbef) had more stenosis evident on preoperative arteriograms (64.7% +/- 14.55% maximum single diameter stenosis) and a greater average increase in ICF (151% +/- 159%) than those with SF < or = ICFbef (43.3% +/- 20.9% stenosis and 34% +/- 54% increase in ICF), suggesting that the relationship between SF and ICFbef defines groups with different hemodynamic responses. The similarity between SF and ICFbef indicates that Javid shunt flow offers adequate protection from cerebral ischemia. A practical benefit of the shunt clamp-on flow probe is the ability afforded to recognize shunt occlusions.

Anastomosis, Surgical↗
PubMed1994

Determinants of patency after percutaneous angioplasty and atherectomy of occluded superficial femoral arteries.

BACKGROUND: Patients undergoing percutaneous recanalization of chronically occluded superficial femoral arteries were studied to determine which factors correlated with 1-year patency. Immediate change in ankle:brachial index (ABI), length of occlusion, tibial run-off, and the performance of supplemental catheter atherectomy were evaluated. METHODS: Eligible patients had at least one patient tibial run-off vessel and the absence of limb-threatening ischemia. Recanalization was performed via passage of a guidewire followed by balloon angioplasty. Tibial run-off was scored based on a modification of the angiogram scoring system of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery. Supplemental transcutaneous extraction catheter atherectomy was randomly assigned to a sub-group of patients after initial experience with the recanalization technique. Clinical follow-up was employed to determine patency. RESULTS: Forty-two of 57 attempts (74%) at recanalization were immediately successful. Overall 1-year patency was 40% in 40 limbs that could be followed. In limbs with balloon angioplasty alone (n = 23), patency was 43% compared with 35% in those having supplemental atherectomy. Tibial run-off did not vary significantly between patent and occluded groups. When ABI increased by 0.3 or more, patency was 56% compared with 26% when the ABI increase was less than or equal to 0.1 (P = 0.13). Occlusion length averaged 18.1 +/- 10.6 cm for all limbs and did not vary significantly between early successes and failures. Limbs with short occlusions (less than or equal to 5 cm, n = 8) had 63% patency compared with 38% patency for limbs with long occlusions (greater than 25 cm, n = 16), but the difference was not significant by analysis of variance. CONCLUSIONS: An initial change in ABI was most predictive for patency, whereas no correlation with tibial run-off was demonstrated. Atherectomy did not increase patency. Short occlusions were more likely to remain patent than long ones, but overall patency was lower than described in other series.

Analysis of Variance↗
PubMed1994

Changes in internal carotid blood flow after carotid endarterectomy correlate with preoperative stenosis.

BACKGROUND: The relationship between preoperative stenosis and the effect of carotid endarterectomy (CEA) upon internal carotid blood flow (ICF) is not well understood. With the intention of better characterizing this, we compared intraoperative measurements of internal carotid blood with the maximum single diameter stenosis found in preoperative angiograms. METHODS: Fifty-two patients undergoing 64 carotid endarterectomies (12 bilateral) had transit-time ultrasound perivascular probes used to measure ICF before and after CEA, and the percent change in ICF (% delta ICF) achieved was calculated. Maximum single-diameter stenosis was determined by comparing the least diameter in the flow path from the common carotid to the normal-appearing internal carotid just distal to bifurcation disease. RESULTS: The entire group had a mean of 53 +/- 21% stenosis found on preoperative angiograms, and % delta ICF averaged 64 +/- 92%. When divided into subgroups based on degree of stenosis, patients with 0% to 40% stenosis (n = 17) had % delta ICF of 32 +/- 46%, patients with 41% to 70% stenosis (n = 30) had % delta ICF of 72 +/- 105%, and patients with more than 70% stenosis had % delta ICF of 168 +/- 160%. The differences in % delta IC were significant for the > 70% group compared with the other groups (analysis of variance, P < 0.005), and marginally significant (P = 0.056) between the 0% to 40% and the 41% to 70% groups. The scatter plot of % delta ICF versus stenosis showed a significant second order direct correlation (r = 0.428, P < 0.001) and disproportionate increases in ICF above 60% stenosis. CONCLUSION: A curvilinear relationship between stenosis and immediate increase in ICF after CEA was demonstrated in agreement with theory, and in those patients with more than approximately 60% single-diameter stenosis, large disproportionate increases in blood flow were more frequently observed.

Analysis of Variance↗
PubMed1993

Changes in renal vein, renal surface, and urine oxygen tension during hypoxia in pigs.

To determine whether ureteral urine oxygen tension could serve as a monitor of renal hypoxia and its relationship to other renal O2 tension parameters, we simultaneously measured femoral artery (PaO2), renal vein (PrvO2), renal surface (PrsO2), and ureteral urine (PuO2) oxygen tensions in 8 anesthetized pigs while incrementally decreasing the inspired oxygen concentration (FiO2) from 21% to 12%. Renal artery blood flow, measured by transit time ultrasound, renal oxygen consumption, and thermodilution cardiac output, was constant. Changes in PaO2, PrvO2, PrsO2, and PuO2 caused by decreasing FiO2 were evaluated by one-way analysis of variance. The relationships between PuO2 and the other O2 tension parameters were evaluated by correlation coefficient and linear regression statistics. Of six possible O2 decrements (combinations of 3, 6, and 9%), only PrvO2 significantly decreased with all six decrements. PuO2 decreased when FiO2 decreased 6% or more. PuO2 is not a sensitive indicator of systemic hypoxia. Under constant renal perfusion and oxygen consumption, PuO2 had a correlation coefficient of 0.80 and a regression equation of PuO2 = 0.84 (PrvO2) + 11.6, with PrvO2. PuO2 is related to PrvO2 when renal perfusion is constant.

Animals↗
PubMed1992

Anatomic and functional assessment of stenosis severity with intravascular ultrasound imaging in vitro.

An in vitro study was performed to evaluate the accuracy of intravascular ultrasound imaging compared with roentgenography for determining the cross-sectional area of a lumen; and to determine if the functional significance of an irregular stenosis is predicted more accurately by intravascular ultrasound than roentgenography. Varying degrees of stenosis were made in 17 rubber tubings by adjusting a plastic constrictor. The cross-sectional areas at the normal and the stenotic segments were determined by intravascular ultrasound, roentgenography, and then measured directly from an acrylamide gel cast of the lumen. To evaluate the functional significance of a stenosis, the pressure drop across the stenosis was measured using a fluid pumping circuit. The actual pressure drop was then compared with the predicted pressure drop derived from hydrodynamic equations using cross-sectional areas obtained by intravascular ultrasound or roentgenography. There was an excellent correlation between the cross-sectional areas at the tightest stenosis measured by intravascular ultrasound compared with the area from the acrylamide cast (7.2 +/- 2.6 v 6.6 +/- 2.4 mm 2, mean +/- SD, r = .93). Measurements of cross-sectional area from the roentgenograms (10.9 +/- 3.9 mm 2) also provided a relatively good correlation with those from the acrylamide casts (r = .84); however, the roentgenograms consistently overestimated the cross-sectional area of the stenosis. The mean values of the actual pressure drop and the predicted pressure drop by intravascular ultrasound and roentgenograms were 15.7 +/- 13.5, 11.3 +/- 11.9, and 4.3 +/- 4.5 mmHg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1991

Cytologic detection of colorectal cancer after administration of oral lavage solution.

Whether malignant cells can be detected in the bowel movements induced by oral gut lavage solution administration was studied in patients with known colonic adenocarcinomas. The induced bowel movements were collected in 27 patients, nine of whom had cancer proven by anatomic pathologic examination. The cells present were recovered with a simple technique and stained by the Papanicolaou method. Malignant cells were identified in the stained preparations in all nine patients with cancer (100% sensitivity), and there were few false positives (94.5% specificity). The authors concluded that if additional studies with greater numbers of subjects confirm the reliability of this technique, a test may be developed that would be useful for either early detection or screening.

Adenocarcinoma↗
PubMed1990

Women's knowledge of Papanicolaou smears.

In this survey women were questioned about their knowledge of Papanicolaou (Pap) smears. The findings demonstrate that women have a reasonably good general knowledge about Pap smears but a poor specific knowledge. These results have important public health implications and emphasise the need for greater communication between doctor and patient.

Adolescent↗
PubMed1987

Pharmacokinetics of hexamethylmelamine in intralipid following hepatic regional administration in rabbits.

Hexamethylmelamine (HMM) is a cytotoxic agent demonstrated to have broad antitumor activity. Poor solubility in aqueous media has precluded significant evaluation of parenteral administration of this drug. A formulation of HMM dissolved in Intralipid has demonstrated excellent tolerance following parenteral administration. The goal of this study was to evaluate the pharmacology of HMM in Intralipid following hepatic regional administration. The routes of administration were intraarterial via the hepatic artery with and without arterial occlusion, i.v. via the portal and jugular veins, and i.p. All animals received a total dose of 10 mg HMM/kg of body weight. Hepatic extraction of HMM was most evident via the portal vein (PV) route [AUC(PV)/AUC(i.v.) = 0.5; P less than 0.05]. Lower plasma levels and areas under the curve (AUCs) were observed for the hepatic artery and hepatic artery-stop flow groups when compared to i.v., but the difference was not significant. Administration i.p. yielded low plasma levels but a very long half-life (88 min). Hepatic tissue levels were highest in the group receiving HMM by the hepatic artery-stop flow route. We conclude that the HMM-Intralipid mixture is well tolerated, that HMM is extracted to a significant degree by the liver following PV administration, and that an i.p. installation of HMM-Intralipid results in prolonged plasma drug levels. This preclinical study supports further efforts at evaluation of parenteral administration of the HMM-intralipid mixture.

Altretamine↗
PubMed1977

Human B lymphocytes in giemsa stained preparations.

A mixed antiglobulin procedure has been developed to provide simultaneous study of cell surface immunoglobulin and detailed cytological features in Giemsa stained preparations. The percentage of surface immunoglobulin bearing lymphocytes, monocytes and granulocytes changed dramatically when lymphocytes were incubated at 37 degrees C, or following sheep erythrocyte rosette enrichment procedures.

Animals↗