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Biomedical subjects

G J Collins

Publications and source records attributed to G J Collins.

At least 55 records · Page 3Linked to original sources
PubMed1979

Popliteal vascular entrapment. Its increasing interest.

In the past 20 years since the first clinical management of a patient with a congenital anomaly associated with an abnormal medial head of the gastrocnemius muscle causing external compression on the popliteal artery, approximately 100 similar lesions have been documented in the world's literature. This has been a lesion of international interest, with only approximately 25% of the cases from hospitals in the United States. This present series of 14 lesions from Walter Reed Army Medical Center, Washington, DC, during a 12 1/2-year period beginning in September 1966 emphasizes the increasing interest in this lesion. The young athletic male in whom intermittent claudication develops with strenuous exercise or the middle-aged patient with a popliteal aneurysm should be evaluated for the possibility of popliteal vascular entrapment. Medial deviation of the popliteal artery seen angiographically is a classic finding, however, there might also be segmental occlusion of the midpopliteal artery. This series outlines various types of popliteal vascular entrapment and documents successful surgical management.

Adult↗
PubMed1979

Coverage of exposed vascular conduits.

When a vascular conduit becomes exposed, it is generally thought that if it is not already infected, it will soon become so. The most comprehensive treatment would be removal of the prosthesis, debridement of the wound, and extraanatomic bypass. Occasionally, however, extraanatomic bypass cannot be done. In such cases, local measures, such as skin grafting or skin flap coverage, may be used. Our two cases illustrate that these procedures can, on occasion, provide long-term coverage of exposed vascular conduits.

Adult↗
PubMed1979

Phleborheographic diagnosis of venous obstruction.

Between February 1977 and May 1978, phleborheograms were done on 328 extremities. Interpretable tracings were obtained in 322 (98.2%). Results were positive for 102 extremities, negative for 220 extremities, and equivocal or uninterpretable for six extremities. Phlebograms as well as phleborheograms were done in 64 extremities. Phlebograms were positive in 41 and negative in 23. The overall agreement between the interpretations of the phlebograms and phleborheograms was 95.3%. The phleborheogram was positive in each case in which the phlebogram was positive. In three cases with negative phlebograms the phleborheogram was positive. Thus, the sensitivity was 100%, and the specificity was 87%. Phelborheography is a useful ajunct to the diagnosis of venous obstruction. It has a high degree of sensitivity (100% in our experience). Clinical correlation is necessary to determine the most likely cause of venous obstruction in individual cases.

Evaluation Studies as Topic↗
PubMed1979

Ocular pneumoplethysmography: detection of carotid occlusive disease.

To determine the accuracy of ocular pneumoplethysmography (OPG-Gee) in detecting carotid arterial occlusive disease, 350 patients were tested by OPG-Gee. Sixty-three patients underwent angiography and the findings were correlated with the results of OPG-Gee tracings. Testing without carotid compression averaged three minutes and was easily performed by a physician or technician. There were no significant complications. Hypertension did not affect evaluation. There were two false-negative tests and no false-positive tests. Without carotid compression the overall accuracy for testing for significant arterial stenosis was 97%. When a carotid compression test was added, the two missed lesions were detected.

Carotid Artery Diseases↗
PubMed1979

Effects of aspirin and dextran on patency of bovine heterografts in the venous system.

The effect of short-term treatment with aspirin or dextran on the patency of bovine heterografts in the venous system was investigated. Animals treated preoperatively and for three days postoperatively with either aspirin (600 mgm BID) or low molecular weight dextran (500 cc/day) had statistically significant increased graft patency as compared to controls during the treatment interval. Significance was lost, however, after cessation of therapy. These results suggest that either aspirin or low molecular weight dextran would be useful adjuvants to venous reconstruction. If used in the venous system, bovine heterografts might be expected to yield better short term patency with adjuvant therapy employing either dextran or aspirin.

Administration, Oral↗
PubMed1979

Nondialysis uses for vascular access procedures.

Chemotherapeutic agents, blood products and hyperalimentation solutions have been administered and recurrent diabetic ketoacidosis has been treated via vascular access procedures in 13 patients during the period from 1972 through 1977. Bovine heterograft, saphenous vein graft and the direct arteriovenous fistulae have been successfully utilized in the construction of arteriovenous fistulae in patients requiring vascular access for nonhemodialysis purposes. Operative techniques and therapeutic usefulness are discussed.

Animals↗
PubMed1979

Gas-liquid chromatographic/mass spectrometric screening method for T-2 toxin in milk.

A method for the analysis of T-2 toxin in milk is presented. Ethyl acetate extracts of milk samples which had been spiked with T-2 toxin were purified by thin layer chromatography and derivatized with N,O-bis(trimethylsilyl)acetamide to produce the T-2 toxin trimethylsilyl ether (T-2 toxin-TMS). N,O-bis(trimethylsilyl-d9)acetamide was used to make T-2 toxin d9-trimethylsilyl ether (T-2 toxin-d9 TMS) which was added to the derivatized milk extract as an internal standard. Samples were analyzed by combined gas-liquid chromatography/mass spectrometry using either electron impact ionization or chemical ionization mass spectrometry. In electron impact ionization analyses, simultaneous monitoring of the T-2 toxin-TMS fragment ion at m/z 436 and the T-2 toxin-d9TMS fragment ion at m/z 445 gave a T-2 toxin-TMS detectability estimated at 6 microgram/kg. In chemical ionization analyses, the T-2 toxin-TMS fragment ion at m/z 377 and the T-2 toxin-d9TMS fragment ion at m/z 386 were simultaneously monitored to give a T-2 toxin-TMS detectability estimated at 3 microgram/kg. Average recovery was 85% at 200 microgram/kg and 65% at 20 microgram/kg.

Animals↗
PubMed1978

Staged aortofemoropopliteal revascularization.

Staged proximal and distal revascularization may be required in some patients with combined aortoiliac and femoropopliteal disease due to inadequacy of the profunda femoris artery or distal popliteal arterial disease. When these situations arise, one may expect that the procedures may be performed with very low morbidity (10% in this series) and mortality (0.0% in this series). Moreover, one may expect satisfactory results in most cases. In our series of 20 patients, 72.7% of extremities undergoing distal revascularization after previous proximal revascularization remain improved with over three years' follow-up.

Aged↗
PubMed1978

Complex cerebral revascularization.

Although carotid endarterectomy is the usual technique for treating symptoms related to extracranial arterial occlusive disease, cerebrovascular and upper extremity symptoms caused by lesions of the innominate, common carotid, or subclavian orifices necessitate more complex revascularization techniques. We have treated five patients, three females and two males, with symptoms of cerebrovascular and/or upper extremity ischemia by highly individualized, complex, revascularization techniques. The procedures were amalgamations of carotid-subclavian bypass, carotid-subclavian bypass with carotid bifurcation endarterectomy, subclavian-subclavian bypass, axillo-axillary bypass, and carotid-axillary bypass. The conditions of all patients were greatly improved and four of the five patients became asymptomatic. These procedures seem to be highly effective in relieving symptoms and they minimize the risks of cerebral and upper extremity revascularization.

Adult↗
PubMed1978

Doppler cerebrovascular examination, oculoplethysmography, and ocular pneumoplethysmography use in detection of carotid disease: a prospective clinical study.

To determine the comparative acccuracy of three noninvasive cerebrovascular testing systems, 72 patients underwent complete evaluation by Doppler cerebrovascular examination (DCE), oculoplethysmography (OPG-Kartchner), ocular pneumoplethysmography (OPG-Gee), and angiography. Considering 60% diameter stenosis or more by angiography as a true positive finding, the noninvasive tests of the 72 patients showed the following results: DCE, two false-positive, 17 false-negative, and 53 correct with an overall accuracy of 74%; OPG-Kartchner, six false-positive, four false-negative, and 62 correct with an overall accuracy of 86%; and OPG-Gee, no false-positive, two false-negative, and 70 correct with an overall accuracy of 97%. Independent of noninvasive test results, 57 symptomatic and three asymptomatic patients were selected for carotid endarterectomy. Of these 60 patients, 55 (92%) had positive preoperative OPG-Gee tracings. Noninvasive testing is a valuable carotid endarterectomy. Although considerable carotid ulceration may be undetected by noninvasive study, it was uncommon in this series.

Carotid Arteries↗
PubMed1978

Stroke associated with carotid endarterectomy.

Between 1966 and 1976, eleven strokes occurred in association with 509 carotid endarterectomies performed at Walter Reed Army Medical Center. Contralateral carotid arterial occlusion with unilateral stenosis, bilateral carotid stenoses, or multiple extracranial (with or without intracranial) stenoses were present in all patients in whom stroke developed. Preventable technical factors contributing to or directly causing stroke were identifiable in six of the eleven patients. Better appreciation of the high risks associated with the above arteriographic patterns and elimination of technical mishaps should lead to an improvement in our already respectably low stroke rate of 2.2 per cent.

Aged↗
PubMed1978

Vascular trauma secondary to diagnostic and therapeutic procedures: laparoscopy.

Diagnostic and therapeutic laparoscopy are safe procedures that only rarely cause significant morbidity. However, major abdominal arterial and venous injury may occur, requiring prompt recognition and laparotomy. Direct compression will control major hemorrhage until resuscitation is complete. Vascular repair utilizing principles of proximal and distal control, good exposure, appropriate anticoagulation, and lateral suture technic should result in restoration of normal blood flow without significant sequelae.

Adult↗
PubMed1978

Femorofemoral grafts: the role of concomitant extended profundaplasty.

Twenty-one femorofemoral grafts were placed in high risk patients with symptomatic, unilateral, iliofemoral, arterial occlusive disease. There was 100 per cent immediate postoperative relief of ischemia or improvement in claudication. Three late below-knee amputations have been performed. All other living patients had healed extremities and were ambulatory at last follow-up. Cumulative graft patency determined by the life table method was 95 per cent at twenty-four months. The physiologic "steal" created by a femorofemoral bypass with donor limb and/or outflow stenosis must be considered to prevent clinical donor limb functional impairment. A gradient of 10 mm Hg or less between the radial artery mean pressure and the donor femoral artery ensured adequate donor artery flow without regard to angiographic a-pearance of the donor artery. The crucial technical problem in patients operated on for ischemia was reconstruction of adequate outflow. All but one patient required at least minimal profunda endarterectomy, and nine of seventeen (53 per cent) required concomitant extended profundaplasty procedures.

Age Factors↗
PubMed1978

Acute hemodynamic effects of lumbar sympathectomy.

Lumbar sympathectomy increases total limb blood flow after aortofemoral bypass in a high percentage of cases. This was true in eleven of fourteen extremities (78.6 per cent) in our series even though no specific selection criteria for entry into the study, other than the need for aortofemoral bypass, were used: that is, patients were entered into the study irrespective of preoperative ankle/arm pressure indexes or results of hyperemia testing. Overall, flow rates after sympathectomy was added to aortofemoral bypass were 1.55 times greater than after aortofemoral bypass alone. This degree of augmentation of flow may be important, particularly in cases of limited outflow.

Aged↗
PubMed1978

Iatrogenic internal hernia involving the iliac artery.

Four months postradical lymphadenectomy and pelvic irradiation for Stage I teratocarcinoma of the testis, a patient was found to have an internal strangulated herniation of small bowel beneath the right iliac artery. The operative management is discussed, and the literature is reviewed concerning the etiology of small bowel obstruction in postoperative, irradiated patients and the techniques of peritoneal closure.

Hernia↗