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Biomedical subjects

J J Cranley

Publications and source records attributed to J J Cranley.

At least 19 recordsLinked to original sources

Does the asymptomatic limb harbor deep venous thrombosis?

Deep venous thrombosis (DVT) is a great masquerader that cannot be reliably predicted by a patient's symptoms, history, or risk factors. Bilateral lower extremity duplex ultrasonography scans were made of 2,511 patients and analyzed to identify, if possible, a population in which a unilateral study would be appropriate. A total of 1,086 (43%) patients were found to have deep venous thrombosis--742 (30%) unilateral and 344 (14%) bilateral. Of the patients with DVT for whom side-of-symptom information was recorded, 64% had symptoms referable to the involved extremity and 36% had symptoms referable to the contralateral extremity. Of the 362 patients who had asymptomatic lower extremities, 128 (35%) had DVT. Moreover, clots were found in asymptomatic limbs in an additional 263 patients whose contralateral limb was symptomatic. Logistic regression analysis did not reveal combinations of symptoms and risk factors that could predict DVT. If DVT is suspected, the patient should undergo bilateral lower extremity duplex scanning.

Acute Disease

A comparison of the brain weights of normal, untreated hydrocephalic and treated hydrocephalic rat pups.

The dry brain weights of normal, untreated and treated hydrocephalic pups of Texas, Lewis and Texas/Lewis cross rats aged from 2 to 60 days were compared using the technique of generalised linear modelling. It was found that with increasing age there is a steadily progressive increase in the weight of the brains of the normal animals. The brains of the untreated hydrocephalics showed a normal increase in weight up to about the 25th day but after that whilst the weight continued to increase, it was significantly less than normal. On the other hand the weight gain of the brains of the treated hydrocephalic pups resembled that of the normals and steadily increase in weight throughout the period of observation.

Animals

Upper extremity venous duplex imaging.

Over 500 upper extremities have been imaged with the Duplex Scanner at the John J. Cranley Vascular laboratory. Venous anatomy and imaging techniques are presented. Reference points and zones for localizing abnormal findings are demonstrated. Abnormal venous pathology including case presentations of acute radial, basilic, cephalic, and axillary vein thrombosis are presented. Complications of subclavian and internal jugular vein catheterization are demonstrated. Soft tissue pathology including edema, lymphadenopathy, hematomas, cysts, and abscesses are visualized and differentiated. Duplex use for evaluation of aneurysm, pseudo aneurysm and graft surveillance has been increasing in frequency. Examples are demonstrated.

Arm

Measurement of blood flow rates in the lower extremities with use of a nuclear magnetic resonance based instrument.

Direct, noninvasive measurement of pulsatile blood flow to the human extremity is now possible by means of a flow measurement instrument that is based on the principles of nuclear magnetic resonance. The instrument uses a physically independent calibration module as a primary calibration standard. Volumetric calibration of this module indicates that it is precise and accurate over the range of 0 to 100 ml/min. The calibration module is used, in turn, to calibrate an electromagnetic flow sensor that is incorporated into the instrumentation. The calibration module and the electromagnetic sensor were found to be linearly related over the range of 5 to 100 ml/min, with a regression correlation coefficient of 0.996. The calibrated electromagnetic flow sensor is used as a secondary standard for calibration of the nuclear magnetic resonance sensor. Blood flow measurements, obtained by use of this method, agree closely with those obtained by plethysmographic methods. They differ from the plethysmographic results in that magnetic resonance flows will distinguish between the at-rest blood flow in the normal extremity and the flows seen in the extremity (also at rest) with claudication. Based on the results obtained from studying a limited number of limbs with a high degree of ischemia, the method will not distinguish the limb with ischemia from the limb with claudication. Limitations of the method and refinements required to make the method clinically useful are discussed.

Adult

Lower extremity calf thrombosis: to treat or not to treat?

Seventy-five patients with isolated calf vein thrombi were prospectively monitored with sequential duplex scans at 3- to 4-day intervals. Twenty-four patients (32%) propagated and 11 of these 24 (46%) into the popliteal or larger veins of the thigh. Sex, age, obesity, trauma, estrogen use, malignancy, varicose veins, smoking, surgery, and activity level were not predictive for proximal propagation. Proximal soleal vein thrombi had the highest incidence in both propagating and non-propagating groups. Thrombus extent and bilateral involvement were not predictive of propagation. Five percent (4 of 75 patients) had highly probable ventilation perfusion scans as their initial indication for duplex scanning. Deep vein thrombosis isolated to the calf is not a benign problem. If anticoagulant therapy is contraindicated, the progress of the thrombus can be followed by duplex scanning.

Adult

Comparison of healing of lesions in the calvarium of foetal lambs and young sheep.

This study compares the healing of lesions made in the occipital region of the calvarium of 5 foetal and 4 post-natal lambs. The foetuses, operated on between the 83rd and 91st day of gestation, had a bone flap elevated and the post-natal lambs, aged about 6 weeks, had a craniectomy and replacement of the bone pieces. The foetuses were delivered spontaneously at full-term. All the animals had computed tomographic (CT) scans and, after sacrifice, naked eye examination of the bony lesions. These showed that there was poor ossification of the lesions made in the foetuses compared to those made in the post-natal lambs. These findings need to be taken into account when intra-uterine correction of cranio-facial deformities are being contemplated.

Age Factors

Superficial thrombophlebitis diagnosed by duplex scanning.

Since July 1982, this noninvasive vascular laboratory has performed 12,856 lower extermity venous duplex examinations. All cases of acute venous thrombosis have been categorized and entered into a computer data base. One thousand four hundred twelve examinations were positive for acute venous thrombosis. This report analyzes the laboratory's entire experience with superficial thrombophlebitis (SVT). One hundred eighty-six patients were diagnosed by duplex scanning to have SVT. Women outnumbered men 99 to 87. They were slightly older (average age 58.4 +/- 16.2 years) compared with the men (53.8 +/- 14.2 years). Men were more likely to have a complicated course of SVT (40% vs 22%; p less than 0.01). Complications included either radiographically documented pulmonary embolism or deep venous involvement. Fifty-seven (31%) patients had at least one complication of SVT. A series of predisposing factors was analyzed and six factors were associated with an increased risk of complications. They are bilateral SVT (p less than 0.01), age greater than 60 years (p less than 0.01), male sex (p less than 0.01), history of deep venous thrombosis (p less than 0.01), bed rest (p less than 0.02), and presence of infection (p less than 0.02). Location of thrombus within the greater saphenous vein (35%) was most likely to be associated with complications. Isolated varicosities (8%) were least likely to be associated with complications. Duplex scanning identifies a significant number of complications of patients with SVT and should be obtained in cases of saphenous vein involvement or in the presence of associated risk factors.

Aged

Upper extremity venous thrombosis diagnosed by duplex scanning.

The incidence of axillary-subclavian venous thrombosis continues to rise, while reports of noninvasive methods to diagnose this condition have been sparse. A review of the records of 693 consecutive upper extremity duplex scans was performed, and a diagnosis of acute venous thrombosis was made in 123 of these patients. Of these, 85 involved the axillary or subclavian vein. Use of a central venous catheter was the most common risk factor for axillary-subclavian venous thrombosis. Within this group, 8% had a pulmonary embolism, of which 25% were fatal. Follow-up of patients with axillary-subclavian venous thrombosis at a mean of 2 years revealed that 49% of these patients had died. Of the remaining patients, more than one third had evidence of the post-thrombotic syndrome. Duplex scanning of the venous system provides a safe, reliable, and repeatable method of evaluating and following patients with suspected venous thrombosis of the upper extremity.

Acute Disease

Analysis of 1084 consecutive lower extremities involved with acute venous thrombosis diagnosed by duplex scanning.

A retrospective analysis of 8658 consecutive lower extremity venous duplex scans performed between the years 1982 to 1988 revealed 953 patients with involvement of 1084 extremities with acute deep or superficial thrombi. Records of patients with acute thrombi were then evaluated for the incidence, location, and patterns of distribution. There were 485 women (50.9%) and 468 men (49.1%), with a mean age of 62.9 +/- 16.7 years and 58.8 +/- 15.2 years, respectively. There were 371 right-sided thrombi (180 women and 191 men), 451 left-sided thrombi (235 women and 216 men), and 131 (70 women and 61 men) patients with thrombi in both lower extremities. Women were found to be uniformly older, and the left leg was found to be involved more frequently (p less than 0.05). The overall distribution of the 3169 veins involved with acute thrombi in decreasing order were: popliteal, 16.1%; superficial femoral, 15.0%; posterior tibial, 13.4%; common femoral, 13.2%; greater saphenous, 9.9%; soleal, 9.1%; peroneal, 7.2%; deep femoral, 6.6%; lesser saphenous, 5.7%; anterior tibial, 2.0%; varicosities, 1.6%; and perforating, 0.3%. A different rank order was found in analysis of single thrombus patterns as follows: greater saphenous, 27.5%; soleal, 20.1%; lesser saphenous, 13.4%; varicosities, 8.8%; popliteal, 8.1%; posterior tibial, 9.1%; common femoral, 3.5%; superficial femoral, 4.9%; peroneal, 2.8%; deep femoral, 1.0%; anterior tibial, 0.3%; and perforating, 0.3%. In patients with multiple and bilateral thrombi there was a large number of unique patterns of thrombosis. Locations, patterns, and frequency of acute venous thrombi vary with age, sex, and leg involved. Patterns and statistical analyses of pertinent observations were performed.

Acute Disease

Recurrent calcium emboli in a patient with aortic stenosis.

We report a patient with moderate aortic stenosis who had two episodes of calcium embolus to the left popliteal artery within ten months. This case suggests that calcium emboli can be recurrent and that major calcium emboli should warrant consideration of valve replacement, even in patients with mild aortic stenosis.

Adult

Real-time duplex ultrasound mapping of the greater saphenous vein before in situ infrainguinal revascularization.

From November 1983 through September 1985, 102 greater saphenous veins (GSVs) were assessed and mapped by means of real-time duplex ultrasonic scanning before in situ infrainguinal revascularization. Each GSV was also visually assessed at operation. Eighty-five GSVs were successfully used for infrainguinal revascularization; duplex scanning correctly identified 82 of these GSVs as being acceptable for use in in situ bypass. Seventeen GSVs were unacceptable for in situ bypass; duplex scanning correctly identified 11 of these as being unacceptable. Duplex scanning provides anatomic information about the GSV, including size, patency, course, varicosities, double segments, and tributaries. This information permits the surgeon to perform infrainguinal revascularization expeditiously.

Femoral Artery

The outcome of unilateral occipital lobectomy in 12 foetal lambs in about the 100th day of gestation: a preliminary report.

In this study occipital lobectomies were carried out on 12 foetal lambs on about the 100th day of gestation. Three lambs were born alive and had computed tomographic (CT) scans performed on the 13th or 18th day of life. One lamb was found to have hydrocephalus due to ventriculitis. All three lambs had low attenuation areas on their CT scans suggesting that scarring rather than regeneration of the cerebral tissues had taken place. There was no evidence that accelerated bone healing of the skull had occurred. It is speculated that the lack of regeneration cerebral tissues and poor bone healing may have been due to the procedure being performed at a comparatively late stage of gestation.

Animals

Occipital lobectomies in foetal lambs.

Foetal lambs undergoing unilateral occipital lobectomy have been investigated post-natally with computed tomographic (CT) scans, visual evoked potentials (VEP) recording and histological examination of their brains. Only the lambs operated at about 100th day of gestation have so far had their investigations completed, however, the results in all the lambs suggests that the foetal brain responds to an occipital lobectomy in essentially the same way as the post-natal brain. To date no evidence of regeneration has been found in any of the brains. It seems reasonable to conclude that if the foetal brain responds to lobectomy in the same manner to the post-natal brain, then its response to disease is likely to be similar. If this is so it can be argued that remediable foetal central nervous system abnormalities should be treated as soon as possible, if necessary in utero.

Animals

Analysis of blood clot echogenicity.

The ability of B-mode ultrasound to follow effectively blood clot echogenicity changes over time under conditions of red cell preservation and lysis was evaluated. Blood clots were produced in cellulose dialysis tubing and then placed into appropriate baths of either saline or water. The echogenicity changes were then followed quantitatively using A-mode and qualitatively using B-mode imaging. Blood clots in saline showed an initial decrease followed by a leveling off in echogenicity. Blood clots in water showed a decline in echogenicity throughout the experiment. The A-mode imaging was effectively able to follow blood clot echogenicity changes under these controlled conditions.

Blood Coagulation

Extended study of aneurysm formation in umbilical vein grafts.

The rate of aneurysm formation in umbilical vein grafts has been reported to lie between 1% and 8%. However, in these reported series the number of grafts with aneurysms was related to the number of grafts inserted. When the denominator is changed to patent grafts at a given time period, the incidence changes drastically. In this study, duplex scanning was used to detect aneurysms in patent grafts. Four types of aneurysms--localized fusiform, localized eccentric, diffuse, and anastomotic--were recognized. Excluding anastomotic aneurysms, 33% of the grafts patent at 3 years were aneurysmal; in those patent at 4 years, 45% were aneurysmal; and in those patent at 5 or more years, 65% were aneurysmal. On grounds of theoretical considerations, it is believed that duplex scanning is more reliable than either clinical examination or arteriographic study for detecting these aneurysms. There is now evidence that the supporting Dacron mesh is too weak and must be strengthened. Despite aneurysm formation, the patency rate in our series has remained second only to saphenous vein grafts, as previously reported.

Aneurysm

Efficacy of low-dose streptokinase in acute arterial occlusion and graft thrombosis.

In a review of 35 patients undergoing local thrombolysis using selective infusion of low-dose streptokinase, the overall success rate was 43%. Streptokinase appears to be most effective in occlusion of native arteries, in high-flow segments, and in autogenous saphenous vein grafts. Local streptokinase was least effective in occluded prosthetic grafts in the femoropopliteal segment (19% success). Distal embolization and progression of thrombosis of the distal arterial tree may occur while the patient is undergoing local thrombolysis and may result in limb loss. Hence, local thrombolysis is not recommended when surgical treatment is an alternative. Despite the low dose, systemic fibrinolytic effects and hemorrhagic complications were common occurrences; hence, routine hematologic monitoring is mandatory in patients undergoing lytic therapy with local infusion of streptokinase.

Acute Disease