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Biomedical subjects

W R Flinn

Publications and source records attributed to W R Flinn.

At least 91 records · Page 5Linked 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↗
PubMed1981

Late objective assessment of venous value surgery.

To evaluate the contribution of an isolated femoral venous value to venous hemodynamics, ten patients (12 limbs) who had undergone femoral valve transposition without saphenous vein stripping or ligation of perforators were followed up for 12 to 18 months after surgery. Ascending and descending venography were performed to document anatomic patency. Dynamic venous pressures and venous refilling times were recorded to evaluate muscle pump function and cutaneous congestion, respectively. Signs of venous hypertension and the need for elastic support were noted. No patient attained normal venous pressure at any time after surgery. Normalization of venous refilling time was transient: nine of 12 limbs had reverted to preoperative abnormal levels at 12 to 18 months and all required elastic support. Femoral value reconstruction performed alone for venous stasis is not sufficient. In postthrombotic venous ulcer, incompetent calf perforators remain a central problem.

Femoral Vein↗
PubMed1981

Recognition and surgical management of patent but hemodynamically failed arterial grafts.

During a five-year period, 34 patients had persistence or recurrence of abnormal hemodynamic measurements in limbs after arterial reconstruction depsite graft patency documented by arteriography. Initial operations included aortofemoral (four), femorofemoral (ten), femoropopliteal (18), and femorotibial (two) bypass. Immediate postoperative hemodynamic failure was documented in seven patients by a mean ankle/brachial systolic pressure index increase of only 0.05 +/- 0.04 following the initial reconstruction. The remaining 27 patients had delayed hemodynamic failure; mean increase in ankle pressure was only 0.06 +/- 0.05 from the preoperative period until time of detection of failure (average duration 2.5 years). In all 34 patients, arteriography demonstrated patency of the initial graft. In conjunction with the vascular laboratory examination, arteriography identified the cause of hemodynamic failure to be inadequate inflow in 10 patients, poor outflow in 16, combined inflow and outflow obstruction in one, and graft stenosis in seven. Unrecognized stenosis in areas proximal (two patients) and distal (three patients) to the bypass emphasized the importance of complete biplanar arteriography before initial operation. Reoperation was successful in correcting hemodynamic failure in 26 patients (76.5%) with a mean increase in ankle index of 0.41 +/- 0.15. Operation was technically not feasible in four patients and was not performed in another four patients because of concomitant medical problems. In two of these patients, progression to graft thrombosis was documented. The results of this study suggest that early objective recognition of an anatomically patent but hemodynamically failed graft is possible by frequent noninvasive testing. Prompt investigation by arteriography defines the cause and location of failure, and reoperation restores normal limb hemodynamics. Most important, reoperation permits salvage of the majority of these patent grafts prior to ultimate failure from thrombosis.

Adult↗
PubMed1981

Assessment of donor limb hemodynamics in femorofemoral bypass for claudication.

During a 5-year period (1975 to 1980), 44 patients underwent femorofemoral bypass for unilateral disabling claudication caused by iliac atheroocclusive disease. All patients had complete Doppler arterial examination performed pre- and postoperatively, including segmental thigh and ankle pressure and calculation of an ankle/brachial (A/B) index for each limb. In 37 patients, standard treadmill exercise testing was performed before and after femorofemoral grafting. Hemodynamic improvement in the symptomatic limb was evidenced by an increase in resting A/B index from a mean of 0.54 +/- 0.14 before to 0.76 +/- 0.22 after operation (P less than 0.001). Exercise tests which were abnormal in all 37 recipient limbs preoperatively were improved. Six of the seven unimproved recipient limbs had associated femoropopliteal occlusion. Donor limb mean resting ankle/brachial index fell from 0.93 +/- 0.22 before to 0.83 +/- 0.22 after surgery (P less than 0.05). However, in 13 of 23 donor limbs, exercise response which had been normal before surgery became abnormal. Additionally, in 14 patients with abnormal donor limb exercise response before grafting, seven limbs had a significantly worsening of the exercise response postoperatively. These findings were not related to the patency of the superficial femoral artery in the donor limb. Deterioration in donor limb hemodynamics noted in 20 (45%) of the 44 patients in this series suggests that strict patient selection criteria should be maintained. Unlike in healthy subjects, an arteriographically patent atherosclerosis iliac artery may not support flow requirements of bilateral lower limb exercise.

Adult↗
PubMed1981

Assessment of a modified technique of distal splenorenal shunting.

Warren's distal splenorenal shunt has been effective in treatment of recurrent variceal hemorrhage. To simplify the operative procedure, two alterations in the technique were used in this study. The first was to approach the splenic and renal veins simultaneously through a single inframesocolonic retroperitoneal incision in the plane of the pancreatic fusion fossa. The second was abandonment of the portoazygos disconnection. Since 1974, twenty-nine patients have undergone this modified operation. The patients ranged in age from 21 to 76 years. Fourteen patients had alcoholic cirrhosis, 13 had nonalcoholic cirrhosis, and the etiology was unknown in two. There were 14 Child's class A patients, 12 class B, and three class C. Significant ascites was present at operation in seven patients. Hepatofugal flow was demonstrated angiographically in four patients. The follow-up period ranged from 6 months to 6 years; 19 patients were followed up for 1 year or longer. There were three early postoperative deaths (10.3%), and one patient died 2 months postoperatively. Recurrent variceal bleeding was seen early in one patient and late (2 months) in another. Only one of the surviving patients developed encephalopathy. Technical modification to simplify performance of the distal splenorenal shunt did not compromise the results of the operation. However, four of seven patients with ascites died either immediately or early after the procedure, and two of these four patients also had hepatofugal flow. Ascites and hepatofugal flow may adversely influence the results of the operation.

Adult↗
PubMed1981

Correlation of foot arterial anatomy with early tibial bypass patency.

The detailed arterial anatomy of the foot in severe limb ischemia is not well known. This study was undertaken to define foot arterial anatomy and correlate these findings with the early results (6 months) of femoral-distal bypass. After completion of the bypass, operative arteriography was performed by direct injection of contrast media into the graft. A lateral view of the distal limb and foot was obtained. Foot vessel anatomy was classified into primary and secondary pedal arches, analogous to the superficial and deep volar arches of the hand. For peroneal bypass, special attention was paid to perforating branches and their communications with these two pedal arches. A total of 56 distal bypass operations was analyzed. Femoral--anterior tibial bypass was performed in 26 cases. When either a primary or a secondary pedal arch was intact, early graft patency (6 months) was achieved in 20 of 21 patients. When neither pathway was present, graft failure occurred in four of five cases. Similarly, of 10 femoral--posterior tibial grafts, seven remained patent with at least one pedal arch intact, whereas six of seven grafts failed when neither arch was patent. Bypass to the peroneal artery was successful in eight of nine limbs when a patent primary or secondary arch was reconstituted via either the anterior or posterior perforating branches. None of four peroneal grafts remained patent when both arches were occluded. As a whole, in 40 limbs with either a patent primary or secondary pedal arch, early graft success was achieved in 35 limbs (87.5%). In contrast, in 16 limbs with no patent arch, only two (12.5%) were successfully reconstructed (P less than 0.001). Analysis of the results of femoral-distal bypass based on a single plantar arch as the sole determining anatomic factor in graft patency is not adequate. The secondary pedal arch and communicating branches of the peroneal artery are also of surgical significance. Operative arteriography can define runoff in the foot, and this information has prognostic significance. It may allow rational judgment regarding reintervention in patients with failed grafts.

Adult↗
PubMed1981

Hemodynamic assessment of transluminal angioplasty for lower extremity ischemia.

The results of percutaneous transluminal angioplasty (PTA) for 56 ischemic lower extremities in 51 patients were analyzed. Indications for balloon catheter dilatation were intermittent claudication in 46 limbs (82.1%), rest pain in five (8.9%), and ischemic ulceration in five (8.9%). Balloon dialation was technically successful in 16 of 17 iliac segment lesions (94.1%) with symptomatic improvement in each instance. Nine of the 16 limbs were hemodynamically improved with a significant increase (less than 0.15) in ankle systolic pressure index. Four additional limbs had improvement in the thigh index. The remaining three limbs were hemodynamically unimproved. During average follow-up of 7.1 months, the 13 initially improved limbs remained hemodynamically improved. Thirty-one of 42 femoropopliteal dilatations (73.8%) were technically successful, with uniform symptomatic improvement. Of these 31 limbs, 26 had a significant initial increase in ankle index, one had improvement in distal thigh index only, and the remaining four limbs were hemodynamically unimproved. During mean follow-up of 8.4 months in the 27 limbs that initially were improved after femoropopliteal dilation, the pressure index returned to the pre-PTA level in 12 instances (44.4%). These results indicate that PTA is useful in selected short-segment iliac lesions. Balloon dilation of femoropopliteal lesions was less successful and its application requires further evaluation. This study demonstrates the need for close monitoring of the objective hemodynamic response, as well as symptomatic and angiographic results, in establishing the proper role of PTA in the treatment of lower extremity ischemia.

Adult↗
PubMed1980

Surgical correction of chronic deep venous insufficiency by valvular transposition.

Twelve limbs in nine patients undergoing venous valve transposition in treatment of severe chronic deep venous insufficiency are the subject of this report. Hemodynamic measurements including venous pressure studies, photoplethysmography, directional venous Doppler assessment, and impedance plethysmography were done pre- and postoperatively in each case, as was ascending and descending venography. The surgical technique is described in detail and diagrams illustrate general features of the reconstruction. The results show that a functioning valve in the deep venous system of the lower extremity may reverse pre-operative pathophysiology. This preliminary view of the operation indicates that it may have great promise in the field of direct venous reconstruction.

Adult↗
PubMed1980

Sequential femoral-tibial bypass for severe limb ischemia.

Sequential femoral-popliteal-tibial bypass has been recommended for surgical treatment of severe lower limb ischemia in patients with complex multisegmental arterial occlusion. To evaluate this alternative technique critically, sequential grafting was performed in 40 limbs with severe ischemia manifest by rest pain (20), nonhealing ulceration (eight), or gangrene (12). Measurement of segmental Doppler arterial pressure revealed a significant increase in ankle brachial index from 0.29 +/- 0.15 before operation to 0.93 +/- 0.12 after operation, confirming the hemodynamic improvement among these patients. In the early postoperative period occlusion of the distal graft segment was recognized in 12 patients by a characteristic reduction of the ankle/brachial index (0.50 +/- 0.14), while the low thigh pressures remained unchanged. Recurrent severe ischemia was prevented in most by persistent patency of the proximal graft segment. Overall, significant hemodynamic improvement was achieved in 29 of 38 limbs, a limb salvage rate (76%) comparable to that reported for femoral-distal bypass or femoral-popliteal bypass to an isolated popliteal segment. Early graft failure in this series resulted in major amputation in eight of 16 limbs, a significantly lower rate than for these other techniques. Sequential bypass grafting is a useful alternative method for limb salvage. The preservation of the proximal graft patency after distal segmental occlusion may be an important characteristic of this type of reconstruction.

Arteries↗
PubMed1979

Pelvic hemodynamics after aortoiliac reconstruction.

Changes in blood flow to the pelvis were monitored by measurement of penile blood pressures before and after 38 aortoiliac vascular reconstructions. An increase in penile pressure was noted in 14 patients (37%), a decrease was seen in eight patients (21%), and no change occurred in 16 patients (46%). These changes could have been predicted by matching arteriograms to the surgical procedure performed. Preoperative impotence was present in 27 patients (17%). In this group a postoperative increase in penile pressure was associated with restoration of erectile capability in eight of 11 patients. Only one of 10 patients with an unchanged penile pressure regained sexual potency. In contrast, none of the eight patients whose penile pressures decreased had recurrence of erectile capability. Six of these patients had end-to-end aortobifemoral grafts, and concurrent external iliac disease prevented retrograde flow to the internal iliac vessels.

Aged↗