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Biomedical subjects

H Dardik

Publications and source records attributed to H Dardik.

At least 55 records · Page 3Linked to original sources

Infrapopliteal prosthetic graft patency by use of the distal adjunctive arteriovenous fistula.

From November 1979 through December 1989, 210 distal arteriovenous fistulas were constructed as adjuncts to tibial and peroneal vascular reconstructive procedures in 203 patients threatened with limb loss. Two-year cumulative patency rates were calculated by grouping patients on the basis of changing indications in sequential time periods: group 1 (n = 61): 1979 to 1983, 18%; group 2 (n = 80): 1983 to 1986, 33%; group 3 (n = 69): 1986 to 1989, 44%. Although the therapeutic results observed in these groups are not statistically comparable, they show a perceptible trend. Postoperative arteriography showed that flow is prograde in the distal vessels beyond the distal arteriovenous fistula. Graft surveillance by duplex ultrasonography also confirmed that flow in the distal arteries is prograde and that "steal" does not occur. Peak systolic velocity (174 +/- 38 cm/sec) and mean velocity (92 +/- 23) flow rates are increased in grafts with patent distal arteriovenous fistulas compared to those bypasses with closed distal arteriovenous fistulas (p less than 0.01). There were no differences in the flow measurements for the arteries beyond the distal anastomoses and distal arteriovenous fistulas, confirming the prograde nature of the distal flow. In 22 patients analysis of graft and fistula patency by duplex sonography showed that one fourth of all grafts were patent without fistulas at 1 and 2 years after operation. Alternatively, 68% of patent grafts at 1 year had patent fistulas and 58% had patent fistulas at 2 years. We conclude that the distal arteriovenous fistula will increase graft flow and simultaneously prevent distal arterial overload without causing "steal." This technique should be considered whenever a prosthetic graft is necessary for crural reconstruction and only in selected instances of revascularization with autologous veins.

Adult↗

Transmetatarsal amputation: the role of adjunctive revascularization.

Over a 12-year period, 160 transmetatarsal amputations were performed in patients with peripheral vascular occlusive disease. The following groups were defined: group 1 - nonreconstructable disease (n = 40); group 2 - transmetatarsal amputation in conjunction with distal revascularization (n = 99); group 3 - reconstructable disease but transmetatarsal amputation performed without simultaneous revascularization (n = 21). There were nine early deaths in the entire series, for an operative mortality rate of 5.6%. The lowest rate of transmetatarsal amputation healing (24%) occurred in group 1. An 86% healing rate was achieved in group 3, but in seven cases (33%) some type of revascularization was required within 3 months of the amputation. In group 2 the healing rate was 62% but reached 83% where the bypass remained patent for at least 3 months after the amputation. Long-term patency rates also affected healing. Healing was not influenced by the number of local procedures (single vs multiple). The presence of severe infection or extensive necrosis necessitated open transmetatarsal amputation in 89 cases; the remaining 71 amputations involved primary closure. Since many patients were treated at a time when diagnostic modalities as well as the operative indications and techniques differed somewhat from the current practice, much of the information regarding group I patients in particular should be considered as a negative historical control and any conclusion from our data should be adjusted accordingly. Healing after amputation at the transmetatarsal level can be expected in the majority of instances in which revascularization can be performed with predictable patency, even when the standard criteria for performing such amputations are liberalized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Epidural anesthesia as an adjunct to retroperitoneal aortic surgery.

Recent developments in vascular surgery suggest that the retroperitoneal approach to the aorta and the use of epidural anesthesia for lower limb revascularization are associated with decreased morbidity and shorter hospital stays. By combining these principles, we sought to determine if retroperitoneal aortic surgery could be performed under epidural anesthesia and if this might be advantageous. Over a 16-month period, 57 patients underwent aortic surgery via the retroperitoneal (n = 33) or transperitoneal (n = 24) approach. In the former, epidural anesthesia was employed in 10 patients, general anesthesia in 3, and combined epidural anesthesia and general anesthesia in the remaining 20. In the transperitoneal group, general anesthesia was employed in 21 patients and combined epidural anesthesia and general anesthesia in 3. Both groups were similar in age and gender, but risk factors were predominant in the retroperitoneal group. With the exception of one death due to aspiration, there were no significant differences between the transperitoneal and retroperitoneal groups with respect to overall morbidity, pulmonary complications, and length of stay in the intensive care unit and hospital. Despite these findings, we favor the combination of epidural and general anesthesia for retroperitoneal aortic surgery. Morbidity was significantly decreased (p less than 0.05) in low-risk retroperitoneal patients when combined epidural anesthesia and general anesthesia were employed.

Adult↗

Everted cervical vein for carotid patch angioplasty.

Because of the theoretic benefits of autologous vein we undertook an investigation to evaluate cervical veins (facial, external jugular) as patch material after carotid endarterectomy. A device that stimulated both circumferential fixation by sutures and radial tension exerted on in vivo patches was constructed to measure burst strength of tissue. Mean bursting pressure for groin saphenous vein (n = 10) was 94.5 +/- 15.1 pounds per square inch (psi), 75.5 +/- 8.9 psi for ankle saphenous vein (n = 10), 83.3 +/- 14.5 psi for everted (double layer) cervical vein (n = 5) and 10 +/- 3.3 psi for single layer cervical vein (n = 5). No significant differences between saphenous vein at any level and everted (double layer) cervical vein, but all were significantly different from single layer cervical vein (p less than 0.05). From June 1987 through November 1989, 19 patients underwent 21 carotid endarterectomies complemented with adjunctive everted cervical vein patch angioplasty. Indications for surgery were asymptomatic stenosis (53%), transient ischemic attack (29%), and cerebrovascular accident with recovery (18%). All patients were studied after surgery with duplex scanning. Asymptomatic recurrent stenosis was observed in one patient. Transient hypoglossal nerve dysfunction occurred in one other patient. One postoperative death occurred as a result of massive aspiration. These results indicate that everted cervical vein is comparable to the saphenous vein in resistance to bursting and can yield similar results as patch material after carotid endarterectomy. Accordingly, saphenous vein can be spared and lower extremity incisions avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Cutaneous malignant melanoma.

From January 1973 to December 1985, 136 patients with primary cutaneous malignant melanoma were treated at Englewood Hospital. Pathologic types, methods of treatment, and results are discussed and a comparison of results is made with other institutions.

Adult↗

A decade of experience with the glutaraldehyde-tanned human umbilical cord vein graft for revascularization of the lower limb.

Between October 1975 and November 1985, 907 lower limb bypasses were constructed in 715 patients (799 limbs) with glutaraldehyde-stabilized umbilical veins (UV-G) used as the predominant, or sole, graft material. Each reconstruction was classified in one of eight categories depending on the site of the distal anastomosis: above- and below-knee popliteal, anterior and posterior tibial, peroneal, trifurcation, sequential, and crural (tibial or peroneal) bypasses with adjunctive distal arteriovenous fistulas. Primary and secondary cumulative graft patency rates were determined for each category as well as cumulative actual palliation that combines end points of graft failure, amputation, and death. Half-life patencies for popliteal, tibial, and peroneal bypasses were 6.5, 2.3, and 1.7 years, respectively. Perioperative graft thrombosis occurred in 11% of popliteal reconstructions compared with 22% for the crural group. Nonocclusive graft failure caused by infection, aneurysm, or progressive foot gangrene occurred in 87 grafts (8%). The overall infection rate was 4.3%. Anastomotic aneurysms (1.4%) and strictures (2.1%) occurred infrequently as isolated phenomena. The incidence of graft dilatation and aneurysms assumed significant proportion after 5 years (36% aneurysms and 21% dilation); the diagnosis was particularly facilitated by B-mode imaging. Nevertheless, the overall clinical impact of graft degradation remained minimal (6% after 5 years). Twenty-two of 26 graft aneurysms were excised with successful graft replacement achieved in 10. During this 10-year period, our attitudes did change with regard to the indication for UV-Gs in relation to the maturation of infrapopliteal reconstructive surgery, appreciation of the superior results attainable with in situ saphenous vein, recognition of morphologic changes in long-term UV-G implants, and the growing documentation of poor results with polytetrafluorethylene in the crural position. We believe that UV-G is an acceptable alternative to the absent or deficient autologous vein, particularly in patients with limited life expectancy and where expediency may be a critical factor.

Adolescent↗

Factors affecting the patency of infrainguinal bypass.

Two hundred forty-nine well-characterized difficult distal bypasses, entered into a multicenter dextran 40 trial, were reevaluated after 3 years. Seventy in situ (IS) vein grafts, 49 reversed saphenous (RS) vein grafts, 60 polytetrafluoroethylene (PTFE) grafts, and 70 umbilical vein (UV) grafts were used. Primary and secondary patency rates at 3 years were, respectively, 84% and 90% for IS, 66% and 73% for RS, 35% and 48% for PTFE, and 24% and 32% for UV. Subgroup analysis according to the site of distal anastomosis showed no significant differences in primary patency among these grafts at the above-knee level but significant differences between both vein grafts (IS and RV) and the others (PTFE and UV) below the knee (78% vs 31%, respectively). This difference increased at the tibial level (78% vs 10%) but there was also a significant difference between IS grafts (88%) and RS grafts (63%) at this level. Hazard functional analysis showed all grafts except IS grafts begin to fail at an increasing rate again by 24 months. Although overall results appeared to favor PTFE over UV, 62% of PTFE vs 16% of UV terminated at the above-knee level and the patency results of these two grafts were not significantly different at any level. The only other factor than graft type and distal anastomotic site that consistently correlated with late patency was tobacco use. Diabetic patients actually fared significantly better than nondiabetic patients, presumably because of the higher use of IS grafts and lower use of tobacco. The choice of graft overshadows all other factors affecting patency and its influence is magnified with more distal terminal anastomosis.

Anastomosis, Surgical↗

Continuous epidural anesthesia and postoperative epidural narcotics in vascular surgery.

A combination epidural technique using local anesthetics intraoperatively and morphine postoperatively is shown to offer many advantages. These benefits include inhibition of the surgical stress response, decreased cardiorespiratory depression, decreased blood loss, decreased intubation and pulmonary infection, decreased thromboembolism, decreased hyperglycemic and hypertensive response, nitrogen sparing, a stable resting metabolic rate, prevention of immunosuppression, simplification of cerebral status monitoring, and earlier ambulation and hospital discharge. The main disadvantage in patients undergoing vascular procedures is the risk of epidural hematoma. A review of the literature confirms the extreme rarity of this risk and, in view of the emerging benefits, argues for reconsideration of epidural technique in vascular patients. The addition of epidural morphine to this combined technique affords a postoperative pain-free continuum unmatched by any other method. This significantly decreased pain stress in cardiac patients increases safety and comfort. In conclusion, epidural anesthesia and postoperative epidural narcotics provide a safe and reliable method of management for patients undergoing vascular procedures.

Anesthesia, Epidural↗

Primary and adjunctive intra-arterial digital subtraction arteriography of the lower extremities.

Standard contrast arteriography (SCA) and intra-arterial digital subtraction arteriography (DSA) were performed during a 26-month period in 459 cases. The DSA group consisted of 22 aortoiliac studies, 66 crural-pedal arch studies, and 227 combinations. In addition, postoperative DSA was performed in 42 patients to evaluate graft patency, morphology, and inflow and runoff circulations. There were no significant differences in the quality of the preoperative aortoiliac studies performed by either SCA or DSA although, in select cases, one or the other of these techniques resulted in a superior study. Distal crural-pedal arch visualization was enhanced with DSA compared with SCA (85% vs. 65%) but when both were compared with their corresponding intraoperative completion arteriograms, the interpretive error rates resulted in comparable accuracies, false positive and negative rates, and predictive values. The likelihood of achieving graft patency in patients who have unsatisfactory preoperative visualization of the distal circulation by DSA is reasonable (11 of 27 patients) but inferior to the number obtained when there is adequate DSA visualization (40 of 53 patients). We conclude that DSA is a valuable adjunct to preoperative SCA but should not be used as the sole criterion for the assessment of operability for limb salvage. Intraoperative prereconstruction arteriography or direct surgical exploration of the crural arteries in patients with inadequate preoperative visualization will result in graft patency in a significant percentage of cases. Intra-arterial DSA for postoperative evaluation of lower limb bypass adds another dimension to analysis of graft structure and status of the host circulatory beds and also provides a method for accurate interpretation of postoperative data.

Angiography↗