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Biomedical subjects

J B Ricco

Publications and source records attributed to J B Ricco.

At least 37 records · Page 2Linked to original sources

Renal artery revascularization with polytetrafluoroethylene bypass graft.

Between January 1979 and December 1986, a total of 74 renal revascularizations were performed in 68 patients using the reinforced expanded polytetrafluoroethylene prosthetic graft. These 74 revascularizations represent 29% of 251 surgical renal revascularizations performed during the same period of time. Eight patients had a total of nine revascularizations in the emergency setting (group I) for ruptured suprarenal aneurysm or acute thrombosis of the renal arteries. Only one patient survived and six years later, his anatomic and functional results are satisfactory. Sixty-five revascularizations were performed electively in 60 patients (group II). This group consisted of 19 renal revascularizations alone, and 46 combined aortic and renal revascularizations. One patient died of respiratory complications two months after operation after his thoracoabdominal aneurysm was cured. Early repeat postoperative arteriography showed that six reconstructions had occluded (three major renal arteries, three polar arteries). One patient was lost to follow-up. The remaining patients were followed for a mean of 41 months. Follow-up arteriograms obtained during 1987 showed that there were two late occlusions and two distal anastomotic stenoses. Actuarial patency was 85 +/- 10% at 72 months. Polytetrafluoroethylene prosthetic grafts constitute a reliable material for renal revascularization and combined aortic and renal reconstruction in certain anatomic conditions.

Adult↗

Percutaneous transvenous caval interruption with the "LGM" filter: early results of a multicenter trial.

From September 1985 to December 1986, 100 patients undergoing percutaneous placement of a transvenous "LGM" caval filter were included in a multicenter prospective trial. Peripheral venograms completed by pulmonary arteriography or scintigraphy were obtained for all patients. Eighty-five patients had experienced pulmonary embolism, 59 had iliocaval thrombosis, while 40 had venous thrombosis confined to the lower limbs. In two instances, insertion or passage of the catheter was impossible. Ninety-eight "LGM" filters were placed percutaneously through the internal jugular vein, 82 of which were correctly positioned in the infrarenal inferior vena cava. Eight filters were positioned with a tilt of more than 15 degrees with respect to the vertical axis, five failed to open correctly, and three were incompletely open and tilted. No postoperative deaths were observed; there were two recurrent embolisms, and seven caval thromboses occurred during the year that followed insertion of the filter. The "user-friendliness" and efficacy of this percutaneous filter makes it a treatment of choice in the partial interruption of the inferior vena cava.

Aged↗

Aorto-femoral bypass with polytetrafluoroethylene prostheses: preliminary results in 363 cases.

From October 1977 to October 1982, 363 unilateral aorto-femoral bypasses using polytetrafluoroethylene (PTFE) prostheses were performed for predominantly unilateral aorto-iliac disease. The distal anastomosis was extended into the deep femoral artery in 57% of the patients. The postoperative mortality was 0.5%. The actuarial patency rate after 6 years was 87% in patients with claudication and 77% in those with critical ischemia. No false aneurysm developed. Thrombosis of the prosthesis was due to progression of distal disease, intimal hyperplasia and postural extrinsic compression. The latter seems to be characteristic of PTFE prostheses and can be treated by thrombectomy. In 21 cases a cross-over femoro-femoral bypass was done during the follow-up period because of contralateral progression of disease.

Adult↗

[Interruption of the vena cava inferior. A comparative study of the Adams de Weese clip and the Kimray Greenfield filter].

Efficacy of two methods for interruption of inferior vena cava was compared after insertion of 95 Adams de Weese clips by the sub or trans-peritoneal route and of 72 Greenfield filters usually by a jugular approach. Introducing Greenfield's filter to produce caval interruption did not require modification of operative indications. In contrast, it allowed caval blockade to be performed in more elderly patients, generally in a poorer condition, at the price of higher mortality, due more to the clinical circumstances of the interruption rather than the caval blockade itself. Postoperative follow up showed fewer caval thromboses after Greenfield's filter (15%) than after the pericaval clip (35%).

Adult↗

[Limitations and results of revascularization of the lower extremities of diabetics].

Both the possibility and prognosis of procedures for revascularization of lower limbs are still the subject of discussion. In 1976, Tingaud et al. emphasized the deceptive nature of femorotibial bypass operations, whereas more recently, the inverse position was taken by Logerfo who considered that therapy should be identical for diabetic and non-diabetic arterial diseases. As a function of experience gained in the Hospital Saint-Joseph with vascular surgery in diabetics, results of revascularization in diabetics were compared with those in non-diabetic patients (the possible influence of the type of diabetes-particularly whether insulin-dependent or not- could not be assessed because of the variable use of insulin apart from precise cases).

Diabetic Angiopathies↗

Composite sequential grafts in severe ischemia: a comparative study.

From October 1978 to June 1983, 64 sequential bypass grafts were performed in 59 patients with limb-threatening ischemia. These patients were classified into three study groups as follows: reversed saphenous vein graft alone (12), composite sequential (proximal polytetrafluoroethylene [PTFE] and distal vein) graft (30), and PTFE graft in entirety (22). Graft patency was confirmed in all cases by serial Doppler ankle pressure measurements or by angiography. Cumulative life-table patency rates were then compared over a period of 27 months. The patency rates for composite sequential grafts using a distal short segment of vein were statistically indistinguishable from those for bypasses performed entirely with saphenous vein. These yielded a patency rate of 80% at 1 and 2 years. In contrast, the 1- and 2-year patency rates of the PTFE sequential grafts were 52% and 47%, respectively (p less than 0.05). Composite sequential bypasses using an otherwise inadequate segment of saphenous vein are a sound alternative revascularization procedure, with a patency rate comparable to that of reversed saphenous vein bypasses.

Adult↗

Modified technique of obturator bypass in failed or infected grafts.

The obturator bypass graft operation can be performed in a moderately simplified manner by a technique that allows extension of indications for the procedure beyond situations in which sepsis is present in the groin. Long-term analysis of the results of the cases available for study indicates that the procedure may very well be a permanent reconstruction, and that graft failure results from graft infection or insufficient distal runoff, as in other distal revascularization procedures. No significant change in ankle pressure is noted when the hip is placed in maximum flexion position.

Aged↗

The use of operative prebypass arteriography and Doppler ultrasound recordings to select patients for extended femoro-distal bypass.

Of 113 preoperative arteriograms analyzed, 46 (40%) were unsatisfactory to determine operability for femoral-distal bypass. In 23 of these 46 arteriograms, there was complete nonvisualization of calf vessels (Group A) and in the remaining 23, there was limited visualization (Group B). Both prebypass, on-table operative arteriography and Doppler ultrasound recordings were helpful in predicting the best available artery for bypass in all but one patient (4%) in Group A. In Group B, 7 of 23 patients had the site of distal anastomosis altered after prebypass, ontable arteriography. There was no statistical difference in the patency rates of grafts in patients with inadequate visualization (Groups A and B) and those with adequate visualization (67 patients, Group C). Prebypass, on-table operative arteriography, supplemented by preoperative Doppler ultrasound recordings, helps to extend operability and to avoid unnecessary amputation.

Angiography↗

Hemodynamic assessment of venous problems.

Objective assessment of venous function based on venous refilling time recorded by photoplethysmography (PPG) was done in 89 patients with postphlebitic syndrome (47), primary varicose veins (29), and after an episode of acute deep vein thrombosis (13). Limbs with symptomatic postphlebitic changes had a shortened venous refilling time of 15.6 +/- 11 seconds (normal greater than 20 seconds). When venographic findings (ascending and descending) in 47 patients with postphlebitic syndrome were analyzed, it was noted that femoral valve incompetence demonstrated by descending venography was a common finding (81%), even in asymptomatic limbs (85%). Venous refilling time bore no relationship to the degree of femoral venous valve reflux. However, if there were associated diseased deep veins with incompetent perforating veins, the venous refilling time was much shorter (14 +/- 4 seconds) than in limbs without calf perforating veins (27 +/- 11.9 seconds, P less than 0.05). A tourniquet was used to impede saphenous flow, and changes in refilling time were recorded in 34 limbs with varicosities of the long saphenous vein. Refilling time normalized after tourniquet application in 31 limbs (14.43 +/- 4.34 to 30.64 +/- 11.9 seconds), and all patients underwent vein stripping. Postoperative recording confirmed the improvement in venous refilling time (29.52 +/- 27.8 seconds, P less than 0.05). Thirteen patients with acute deep vein thrombosis had serial PPG tests during a follow-up period of 27 months (mean 15.8 months). Seven had initial abnormal PPG results and persistently abnormal readings, and all developed postphlebitic changes. Venous refilling time is an useful test to determine the hemodynamic significance of femoral venous valve incompetence and to assess the effect of vein stripping on varicose veins. In acute deep vein thrombosis, follow-up study may help to identify patients at risk for development of postphlebitic changes.

Femoral Vein↗

[Results of surgical treatment of aorto-cardiac fistulas].

The authors report their experience in the surgical correction of aorto-cardiac fistulae. The long term results emphasise the good prognosis in coronaro-cardiac fistulae (13 cases), the problems posed by residual aortic insufficiency in the case of ruptured aneurysms of the sinus of Valsalva (37 cases), the difficulties in diagnosis in the presence of an interventricular communication in association and, finally, the rarity of communications between the aorta and left ventricle (4 cases).

Adolescent↗

Temporary liver transplantation in acute liver failure.

The ability of a heterotopic graft to prolong life in animals dying in hepatic coma due to liver necrosis has never been definitely established. Acute hepatic failure was produced in 15 dogs by an hour of total interruption of the hepatic blood supply. Nine dogs received an intrathoracic hepatic homograft concurrently. Nontransplanted dogs died within 21 hours in hepatic coma, while transplanted dogs survived significantly longer (P less than .001). In all transplanted dogs, biological signs of hepatic failure were corrected in 24 hours. In four animals, the graft was removed on the fifth postoperative day. Two of those survived for 10 and 15 days respectively with normal hepatic function. These results demonstrate that a temporary heterotopic liver transplant is able to support life during the acute, normally lethal phase in dogs with massive liver necrosis.

Acute Disease↗

Modifications of 3'-methyl-4-dimethylaminoazobenzene carcinogenesis of rat liver and carcinogen metabolism by portacaval anastomosis.

The effect of portacaval shunt on hepatocarcinogenesis was studied in rats fed 3'-methyl-4-dimethylaminoazobenzene. Portacaval anastomosis resulted in a decrease of hepatocarcinogenesis as reflected by a delay in the early peak of alpha-fetoproteins, an absence of late appearance of alpha-fetoproteins, and a significantly lower incidence of tumors than in nonshunted rats. Reduction of hepatocarcinogenesis in shunted rats was associated with a decrease of the binding of 3'-methy-4-dimethylamioazobenzene metabolites to liver proteins. This effect seemed to be related to modifications of carcinogen-metabolic pathways. While the detoxifying azoreductase activity was not affected by portal diversion, the activating pathway leading to the binding of 4-dimethylaminoazobenzene metabolites to DNA, a major step for cell carcinogenesis that is mediated by microsomal enzymes, was decreased in shunted rats to about 50 percent of control values. The decrease of liver weight that occurred in shunted rats without loss of body weight produced a very significant reduction of the total capacity of liver to activate 4-dimethylaminoazobenzene while the total capacity of detoxification remained unchanged. This could be a direct consequence of portacaval anastomosis, as has been shown for other microsomal enzymes.

Animals↗