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H Dardik

Publications and source records attributed to H Dardik.

At least 37 records · Page 2Linked to original sources
PubMed1996

Improved method to create the common ostium variant of the distal arteriovenous fistula for enhancing crural prosthetic graft patency.

PURPOSE: Successful use of the distal adjunctive arteriovenous fistula (dAVF) for the enhancement of prosthetic graft patency rates in the crural position is critically dependent on the qualitative and quantitative aspects of the arterial and venous runoff. Precise technical performance of the fistula is equally vital to secure optimal results. The purpose of this study was to determine current prosthetic graft patency and limb salvage rates using a modified version of the common ostium dAVF. METHODS: The standard method to create the common ostium variant of dAVF has been modified to improve apposition of the "otomy" sites of the artery and vein, avoid twisting and stenosis by terminating the fistula suture line at the artery-vein junctures, reshaping the ovoid ostium to a rectangular shape, and finally, use of multiple interrupted heel-toe sutures. RESULTS: Since 1979 we have created 290 fistulas in 281 patients who required leg revascularization procedures. In different time periods we have documented improving graft patency and limb salvage rates. Fistula patency, reflected by annual attrition rates of 13% to 26% per year, continues as a challenge for long-term results. Current 3-year secondary cumulative graft patency and limb salvage rates by life table analysis are 61% and 74%, respectively. The conduit material may play a role with regard to steal phenomena and the need for banding techniques. CONCLUSION: Configuration of the adjunctive dAVF may impact on prosthetic graft patency in the crural position. In addition, the type of graft material used for bypass may be instrumental in preventing or precipitating the steal phenomenon. These issues require further study to better understand flow dynamics, patterns of intimal hyperplasia, and blood distribution as a function of conduit material and impedance of the arterial and venous runoff.

Adult↗
PubMed1996

Pelvic radiation therapy as a risk factor for ischemic colitis complicating abdominal aortic reconstruction.

Ischemic colitis is an infrequent but potentially devastating complication of abdominal aortic reconstruction. Identification of patients with predisposing risk factors for the development of ischemic colitis can guide intraoperative measures to preserve or restore colonic blood flow during aortic surgery. Previous radiation therapy for pelvic malignancy may be one such predisposing risk factor. Two cases are presented in which ischemic colitis complicated abdominal aortic reconstruction in the setting of previous pelvic irradiation. In the months after radiation therapy for prostate cancer, one patient underwent infrarenal abdominal aortic aneurysm repair. Ischemic infarction of the sigmoid colon developed acutely after surgery and required emergent sigmoid colectomy. The second patient underwent reconstruction of an infrarenal abdominal aortic aneurysm after having had radiation therapy for a bladder tumor. Despite an initial satisfactory result, the patient's abdominal pain and diarrhea progressively worsened and he eventually required sigmoid colectomy for severe ischemic colitis. In both of these patients, the inferior mesenteric arteries were patent and had not been reimplanted. The association of pelvic radiation therapy with ischemic colitis after aortic reconstruction should focus attention to the operative details for maintaining the colonic circulation in these patients. Reimplantation of the inferior mesenteric artery in particular may prevent both the acute and the insidious variants of this complication in patients who undergo aortic surgery and decrease the incidence of this complication in patients with a history of radiation therapy to the pelvis.

Aged↗
PubMed1996

The milk rejection sign: a natural tumor marker.

Early discovery of breast cancer in the lactating female will result in improved survival rates. One such marker is the "milk rejection sign," which has rarely been described and consists of the rejection by the nursing infant of the lactating breast that harbors an occult breast carcinoma. Recognition of this particular sign is vital and will enable early diagnosis and improved prognosis.

Adult↗
PubMed1995

Experience with a new valvulotome for lower-extremity revascularization procedures by the in situ method.

Between November 1990 and November 1992, 50 consecutive cases requiring lower-extremity revascularization by the in situ method were compared with regard to use of two different valve cutters, the Hall valvulotome and the Insitucat. There were no amputations in patients with patent grafts, nor were any infections or false aneurysms noted during the course of this study. In the Insitucat group (n = 25), primary patency was achieved in 19 cases. Five of the six graft failures underwent additional procedures of which three remained patent, adding to the secondary patency rate (22 of 25). The greatest problem with regard to maintaining primary graft patency was that of missed or retained valves, but the incidence of this problem decreased during the course of this study as experience was gained with the catheter in conjunction with angioscopy. Experience with the Insitucat valvulotome has demonstrated its efficacy, though enhanced by monitoring the results with angioscopy. The development and discovery of focal stenotic areas and retained valves by surveillance sonography have resulted in enhanced (assisted) primary graft patency rates. The incidence of these problems appears to be comparable with that occurring with other means of producing valvular incompetence for an in situ reconstruction where valvulotomes of similar design are employed. This was confirmed by comparative analysis with another group of 25 in situ vein bypasses performed during the same time period but during the Hall valvulotome.

Aged↗
PubMed1995

The second decade of experience with the umbilical vein graft for lower-limb revascularization.

Some 20 years have elapsed since the initial concept and development of the human umbilical vein graft. Experience with 1074 umbilical vein grafts forms the basis of this report as the indications for this prosthesis have been refined and its performance defined. In 1988, the author and colleagues published their 10-year experience with umbilical vein which described the results of 907 bypasses constructed in 715 patients (799 limbs). Over the past 5 years, the use of umbilical vein has decreased because of a commitment to autologous saphenous vein. A total of 167 additional umbilical vein bypasses were performed at Englewood Hospital and Medical Center between 1985 and June 1993. Secondary patency rates for popliteal and crural reconstructions at 5 years showed a trend of continuous improvement--65% and 45% respectively compared with 57% and 33% as reported during the first decade of experience. Rates of infection, stenosis and pseudoaneurysm decreased and only two aneurysms have been discovered during this period. Umbilical vein is an acceptable alternative to the absent or deficient autologous vein. Patency rates are second only to autologous vein rates and the fear of failure due to aneurysm formation has not only been overstated, but also significantly exaggerated.

Adult↗
PubMed1995

Mesoportal bypass: a unique operation for mesenteric hypertension.

A 47-year-old man was referred for evaluation and treatment of gastrointestinal variceal bleeding and possible transjugular intrahepatic portal-systemic shunting. Intrahepatic manometry disclosed a normal portal pressure, but selective mesenteric arteriography revealed occlusion of the superior mesenteric, splenic, and inferior mesenteric veins. Duodenal and gastric varices were noted, but no esophageal varices were seen. The portal vein was clearly patent. At surgery, a 2 cm mass was found at the superior mesenteric vein-splenic vein juncture, and subsequent pathologic examination confirmed the presence of suture material within dense fibrous tissue as the probable cause for this rare condition. The surgical procedure performed was a superior mesenteric vein-to-portal vein bypass, employing ringed expanded polytetrafluoroethylene. Graft patency and function have been confirmed postoperatively by means of both venous-phase mesenteric arteriography and duplex imaging. The surgical procedure was novel, in that it was possible to decompress the hypertensive mesenteric circulation from the distal superior mesenteric vein directly into the portal vein with a prosthetic bypass. The physiologic benefit of this operation is clear: the avoidance of the encephalopathic syndrome and the facilitation of hepatopetal blood flow.

Blood Pressure↗
PubMed1993

Laser-assisted fibrinogen bonding of umbilical vein grafts.

Despite success with autologous tissue welding, laser welding of synthetic vascular prostheses has not been possible. The graft material appears inert and fails to allow the collagen breakdown and electrostatic bonding that results in tissue welding. To develop a laser welding system for graft material, we repaired glutaraldehyde-tanned human umbilical cord vein graft incisions using laser-assisted fibrinogen bonding (LAFB) technology. Modified umbilical vein graft was incised transversely (1.2 cm). Incisions were repaired using sutures, laser energy alone, or LAFB. For LAFB, indocyanine green dye was mixed with human fibrinogen and the compound applied with forceps onto the weld site prior to exposure to 808 nm diode laser energy (power density 4.8 W/cm 2). Bursting pressures for sutured repairs (126.6 +/- 23.4 mm Hg) were similar to LAFB anastomoses (111.6 +/- 55.0 mm Hg). No evidence of collateral thermal injury to the graft material was noted. In vivo evaluation of umbilical graft bonding with canine arteries demonstrates that LAFB can reliably reinforce sutured anastomoses. The described system for bonding graft material with laser exposed fibrinogen may allow creation or reinforcement of vascular anastomoses in procedures where use of autologous tissue is not feasible.

Anastomosis, Surgical↗
PubMed1992

Comparative efficacy of topical hemostatic agents in a rat kidney model.

The efficacies of four topical hemostatic agents were compared in a rat model employing a standardized renal injury. The materials used to effect hemostasis were oxidized cellulose, microfibrillar collagen powder, positively charged modified collagen, and single donor heterologous fibrin glue. Animals that were treated only with surgical gauze served as controls. Hemostasis was achieved by application of one of the topical hemostatic agents plus moderate digital pressure. The time necessary to achieve complete hemostasis was recorded for each animal. Control animals bled profusely and suffered an increased postoperative mortality rate compared with the experimental animals. Microscopic studies demonstrated progressive healing of the injuries with varying degrees of inflammation and scar formation. Fibrin glue was by far the most effective agent in controlling hemostasis. The collagen materials, though effective, required a longer time to control bleeding and did not differ statistically in their activity from one another.

Administration, Topical↗
PubMed1991

Interval gangrene of the lower extremity: a complication of vascular surgery.

Interval gangrene, segmental ischemic necrosis proximal to a functioning distal anastomosis, is a rare complication after successful peripheral vascular reconstruction. Previous reports have demonstrated the gravity of this event in that major limb amputation was required in all cases. Two cases are presented to emphasize the need for maintaining segmental collateral circulation after successful distal extremity bypass. Despite a satisfactory result after distal (inframalleolar) bypass of a popliteal aneurysm, one patient had progressive ischemic gangrene of the upper leg and eventually required amputation. The contralateral limb was successfully managed by distal ligation of the superficial femoral artery, which maintained collateral flow from the proximal superficial femoral artery to the knee and leg. The second patient required a microvascular free flap to replace tissue loss and provide vascular graft coverage after initial multiple bypass failures and a final successful remote reconstruction to the dorsal artery of the foot that excluded the popliteal-crural collateral network. Patients with inadequate collateral circulation or disruption of the profundus or geniculate collateral pathways may require revascularization of sequential vascular beds. Recognition of the potential for interval gangrene is essential since the likelihood of its occurrence will increase in proportion to the number of distal bypasses being performed for limb salvage. Although adjunctive procedures will not completely eliminate the possibility of interval gangrene, awareness of this phenomenon with attention to the segmental collateral circulation can decrease the incidence of its occurrence.

Adult↗
PubMed1991

Rupture of arteriovenous fistula after in situ saphenous vein bypass.

Residual saphenous vein tributaries function as arteriovenous fistulas after in-situ lower extremity bypass. Whether or not all of these tributaries need to be ligated at the time of bypass is controversial since many will close spontaneously. Other consequences of retained fistulas range from local skin problems to diminished graft flow and ultimate graft thrombosis. A complication not previously reported is rupture of a retained arteriovenous fistula. This unusual and potentially catastrophic complication should be discoverable at an earlier stage by periodic graft surveillance by means of duplex sonography. The routine policy of selective ligation of saphenous vein tributaries needs to be reexamined.

Aged↗