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Biomedical subjects

R H Samson

Publications and source records attributed to R H Samson.

48 records · Page 3Linked to original sources
PubMed1982

Randomization of autogenous vein and polytetrafluorethylene grafts in femoral-distal reconstruction.

A randomized, prospective, controlled study comparing autogenous saphenous vein and polytetrafluoroethylene (PTFE) grafts in infrainguinal arterial reconstructions has been initiated in three different institutions. A total of 446 operative procedures were divided into six groups, depending on the site of distal bypass insertion into the popliteal or an infrapopliteal artery and on whether the patient received a randomized vein or PTFE graft or an obligatory PTFE graft. The randomized saphenous vein graft patency to infrapopliteal arteries was significantly better (P less than 0.005) at 2 1/2 years than the patency of randomized or obligatory PTFE grafts to the same level. No significant differences between randomized vein grafts and randomized or obligatory PTFE grafts in the femoropopliteal position could be demonstrated up to 2 1/2 years, either above or below the knee. The need for such a study and the limitations of this preliminary report are discussed. The requirement for longer observation of greater numbers of cases is stressed. A current plan for usage of the PTFE graft in the lower extremity is presented.

Adult↗
PubMed1982

Level of amputation after failure of limb salvage procedures.

It has been claimed that the level of amputation is rendered higher by unsuccessful limb salvage bypass procedures. To evaluate this premise, we analyzed 242 major amputations performed for atherosclerotic vascular disease. One hundred and sixty-one amputations were performed as primary operations--50 per cent being below knee and 50 per cent, above knee amputations. Eighty-one amputations followed failure of an arterial revascularization. Twenty-three amputations, 13 below knee and ten above knee, followed late closure of such bypass procedures. Early failure of the bypass in 58 patients resulted in 46 below knee and 12 above knee amputations. After failure of 45 bypasses to arteries distal to the popliteal, 14 of the patients required above knee amputation. Following 28 unsuccessful femoropopliteal bypasses, only two patients needed above knee amputation. Thus, the risk of jeopardizing the knee joint should not be considered a major contraindication to limb salvage procedures, especially if a femoropopliteal bypass is contemplated.

Amputation, Surgical↗
PubMed1981

Spontaneous resolution of popliteal artery thrombosis.

Spontaneous resolution of thrombosis of the systemic arteries is a rarely documented phenomenon. Two patients are described in whom thrombus within the popliteal artery was noted to lyse spontaneously. This resulted in a decrease in ischemic symptoms and was documented by angiography. The spontaneous improvement that occurs in some patients with atherosclerotic femoropopliteal disease may be due to this mechanism as well as to increased flow via collateral vessels.

Aged↗
PubMed1981

Progress in limb salvage by reconstructive arterial surgery combined with new or improved adjunctive procedures.

In the past nine years, 1196 patients whose lower extremity was threatened because of infrainguinal arteriosclerosis have been treated at Montefiore Hospital. In the last six years, limb salvage was attempted in 679 or 90% of 755 patients. Femoropopliteal (318), small vessel (204) and axillopopliteal (29) bypasses were used along with transluminal angioplasty (128) and aggressive local operations to obtain a healed foot. Immediate (one month) limb salvage was achieved in 583 or 86% of the 679 patients in whom revascularization was possible. The 30-day mortality rate was 3%. The cumulative life table (LT) survival rate of all the patients undergoing reconstructive arterial operations was 48% at five years. The cumulative LT limb salvage rate after all reconstructive arterial operations was 66% at five years. The cumulative LT patency rate of femoropopliteal bypasses was not influenced by angiographic outflow characteristics of the popliteal artery but was increased 15% by appropriate reoperations to 67% at five years. Cumulative LT patency and limb salvage rates of small vessel and axillopopliteal bypasses were more than 50% at two years. Of patients undergoing arterial reconstruction, 88% of those who died within five years did so without losing their limbs. Of all the patients in whom limb salvage was attempted, 68% lived more than one year with a viable, useable extremity, and 54% lived over two years with an intact limb. We believe this aggressive approach to limb salvage is justified, and can be undertaken with a low cost in mortality, knee loss and morbidity.

Aged↗
PubMed1981

Superficial femoral and popliteal arteries as inflow sites for distal bypasses.

In a series of limb salvage bypass to the popliteal and infrapopliteal arteries, the superficial femoral and popliteal arteries were used preferentially to provide inflow if these vessels were no more than minimally diseased proximal to the site of bypass origin. Cumulative life-table patency rate at 6 years for popliteal bypasses was 66% for 290 cases originating from the common femoral and 81% for 60 cases originating from the superficial femoral and popliteal arteries (P greater than 0.1). Infrapopliteal bypass patency rate at 5 years was 50% for 129 cases originating from the common femoral artery and 58% for 79 cases originating more distally (P greater than 0.25). When vein grafts alone were considered, patency rates were still not influenced by the site of origin of popliteal and infrapopliteal bypasses. Only 1 of 32 failures of a bypass with a distal origin could have been caused by proximal progression of disease. Because of these findings and multiple advantages that result from using arteries distal to the common femoral for bypass inflow, preferential use of the superficial femoral and popliteal arteries for this purpose is recommended in appropriately selected patients.

Adult↗
PubMedDate not supplied

Photoplethysmographic evaluation of external compressive therapy for chronic venous ulceration.

The photoplethysmograph (PPG) was utilized to evaluate the role of external compression in the treatment of chronic venous insufficiency with ulceration (CVIU). Thirty patients with long standing CVIU were evaluated using a PPG probe placed just above the medial malleolus. Venous recovery time (VRT) was calculated after 5 active dorsiflexions. Patients were then retested after an Unna boot had been applied and again, after this had been supplemented by a tight elastoplast wrap. VRT in 10 normal control subjects was greater than 12 seconds (12-30 seconds, mean 19+/-5 seconds). VRT was less than 12 seconds in all tested patients (0-11 seconds, mean 5+/-2 seconds). When an Unna boot was applied, VRT increased to 7+/-2 seconds in 20 patients. An Unna boot and elastoplast wrap increased VRT to 10+/-3 in 25 patients (p less than 0.01).

Bandages↗
PubMedDate not supplied

Five year experience with axillopopliteal bypasses for limb salvage.

Over the last 5 years, we have performed 34 axillopopliteal bypasses to salvage threatened limbs of patients in whom standard anatomic or extra-anatomic bypasses had either failed or were not feasible. The indications for these axillopopliteal bypasses, all of which were performed with 6 mm polytetrafluoroethylene grafts, were: (1) severe atherosclerotic disease of the common, superficial and deep femoral arteries which precluded use of these vessels for inflow or outflow for a standard vascular procedure (15 cases); (2) failed aortofemoral bypass with sufficient fibrosis or disease progression in the profunda femoris artery to prevent its use in a reoperation (7 cases); (3) insufficient hemodynamic improvement and failure to heal a foot lesion after an axillofemoral bypass (9 cases); and (4) sepsis in the groin from a previously infected bypass (3 cases). Graft patency was determined by objective measures. Cumulative life table graft patency rates were 77% at 1 year, 51% at 3 years, and 45% at 5 years. Although these rates are not as good as those for our axillofemoral bypasses (75% at 5 years), 22 limbs revascularized by axillopopliteal bypasses were salvaged with function for 1 year and 9 were salvaged with function for 2 years or longer in situations in which no option other than amputation was available. This justifies the continuing use of axillopopliteal bypass in an effort to salvage those limbs imminently threatened with amputation and in which no standard reconstruction is feasible because of disease or infection.

Aged↗
PubMedDate not supplied

Six year experience with expanded polytetrafluoroethylene arterial grafts for limb salvage.

We have used 822 polytetrafluoroethylene (PTFE) grafts in arterial reconstructions for limb salvage over the last 6 years at Montefiore Medical Center-Albert Einstein College of Medicine, Four hundred and twenty-seven femoropopliteal reconstructions with PTFE had a 6 year cumulative life table patency rate of 55% with follow-up of 76 grafts for more than 3 years and 28 grafts for more than 4 years. Seventy-nine bypasses to the isolated popliteal segment had a 6 year cumulative patency rate of 72%. There were 207 bypasses performed to the tibial, peroneal or dorsalis pedis arteries. Life table patency rates were 55% at 1 year, 40% at 2 years and 37% at 4 years. Ninety-two PTFE femorofemoral and 62 axillofemoral bypasses had 5 1/2 year cumulative life table patency rates of 83% and 75%, respectively. Axillopopliteal PTFE bypasses can salvage otherwise doomed limbs. Thirty-four such grafts had 74% 1 year and 45% 5 year patency rates. The overall infection rate in all 822 PTFE grafts was only 0.5%. Thus, PTFE is a promising vascular prosthetic material which facilitates otherwise difficult or impossible limb salvage procedures.

Adult↗
PubMedDate not supplied

Diagnosis and management of failing lower extremity arterial reconstructions prior to graft occlusion.

In 191 instances, infrainguinal graft occlusion was presumed because of a rethreatened foot, diminished pulses and/or decreased ankle pressure. Routine urgent arteriography revealed 38 instances where the graft was patent (22 vein, 16 PTFE). Ten of these grafts were to the femoral artery, 18 to the popliteal artery and 10 were to infrapopliteal arteries. The deterioration despite a patent graft was due to development of inflow stenosis (15), vein graft lesions (13) or distal disease progression (10). All were treated successfully by percutaneous transluminal angioplasty (30) or simple local operative revisions (8). Cumulative life table patency rates 2 years after reintervention were 89% for failing reconstructions to the femoral artery, 94% for those to the popliteal artery and 89% for infrapopliteal procedures. Comparable rates for limb salvage were 90%, 100% and 100%, respectively. These findings underscore the importance of urgent angiography in suspected lower extremity graft failure. Defects may be detected before real graft occlusion occurs and appropriate interventional treatment can provide important additional periods of limb salvage.

Angioplasty, Balloon↗