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Biomedical subjects

R F Kempczinski

Publications and source records attributed to R F Kempczinski.

At least 37 records · Page 2Linked to original sources
PubMed1991

Complications of anomalous origin of the right subclavian artery: case report and review of the literature.

A 35-year-old black woman presented with thrombosis of an anomalous right subclavian artery and distal arterial embolization. Initially, her right subclavian artery was reimplanted onto the common carotid artery, and a brachial artery embolectomy plus intraoperative thrombolytic therapy were used to reopen her distal arterial circulation. When her brachial artery repair thrombosed the following day, a distal ulnar artery bypass and repeat thrombolytic therapy were required to restore arterial patency. Six months later, she returned with severe, progressive, neointimal hyperplasia of her brachial artery and a second attempt at arterial reconstruction was unsuccessful. She eventually required a right below-elbow amputation. This patient demonstrated an anomalous right subclavian artery that presented with distal embolization without an antecedent history of severe atherosclerotic disease or the development of a right subclavian artery aneurysm. A review of the medical literature relating to complications of this anomaly is provided.

Adult↗
PubMed1991

Temporary closure of the abdominal wall by use of silicone rubber sheets after operative repair of ruptured abdominal aortic aneurysms.

Management of patients after operative repair of abdominal aortic aneurysms can be further complicated if primary closure of the abdominal wall cannot be technically accomplished or is associated with profound increases in intraabdominal and peak inspiratory pressures. We recently treated five patients with ruptured abdominal aortic aneurysms and one patient with a ruptured thoracoabdominal aneurysm whose abdominal incisions had to be closed with a Dacron reinforced, silicone sheet. All patients were hemodynamically unstable either at admission to the hospital or became so during operation. Four patients required the insertion of a silicone rubber sheet at the primary operation because of massive retroperitoneal hematoma or edema of the bowel wall or both. Incisions in two patients were closed primarily, but the patients required reexploration and secondary closure with silicone rubber sheets because of the development of marked increases in peak inspiratory pressures, intraabdominal pressures, and decreased urinary output. Four of the six patients subsequently underwent successful removal of the silicone rubber sheets with delayed primary closure of the abdominal wall, and two others died before removal. The patient with the ruptured thoracoabdominal aneurysm died on postoperative day 20 because of pulmonary sepsis but had a healed abdominal incision. The three surviving patients have been discharged. A silicone rubber sheet may be necessary for closure of the abdominal wall after repair of ruptured abdominal aortic aneurysm in patients where primary abdominal wall closure is impossible or where it results in compromise in respiratory or renal function.

Abdomen↗
PubMed1991

Entrapment of the popliteal artery.

Although entrapment of the popliteal artery is uncommon, it is an important cause of arterial insufficiency in younger patients. Accurate diagnosis depends on a high index of suspicion combined with dynamic noninvasive testing and "stress angiography." Although angiographic demonstration of medial deviation of the artery is diagnostic, absence of this finding does not exclude the diagnosis of entrapment of the popliteal artery. Positional angiography may be necessary in these instances. Surgical exploration should be performed by a posterior approach, since this facilitates identification of the precise anatomic variant while allowing easy arterial repair, if necessary. The condition of the popliteal popliteal artery must dictate the extent of the surgical procedure. If the popliteal artery is normal, then relief of the constricting lesion alone will suffice. If the artery appears diseased or is thrombosed, then myotomy and arterial reconstruction must be performed. This is best accomplished by bypass grafting using autogenous vein or artery. If thromboendarterectomy is used, the clinician can expect a higher percentage of acute postoperative thromboses.

Adolescent↗
PubMed1991

Prevalence of hemodynamically significant stenosis of the carotid artery in an asymptomatic veteran population.

The results of previous studies have suggested that significant stenosis of the carotid artery occurs in less than 6 per cent of asymptomatic patients. However, some populations studied were not representative of those seen by most vascular surgeons. Accordingly, we examined two cohorts of patients at the Veterans Administration Medical Center using Duplex scanning. There were 153 volunteers in group 1, all more than 50 years of age, who were being treated at our outpatient department for nonvascular problems. There were 116 patients of similar age in group 2 but who were known to have significant arterial occlusive disease of the lower extremity. The majority of patients were men with a mean age of 64.4 years. Risk factors in the total population included hypertension, diabetes mellitus, coronary arterial disease, peripheral vascular disease and smoking. Over-all, significant (greater than 50 per cent diameter) stenosis of the carotid artery was discovered in 25 of 269 patients. The prevalence for those in group 1 was 6.5 per cent versus 12.9 per cent for those in group 2 (p = 0.058). The prevalence in patients with cardiac disease was 15.2 per cent compared with 6.8 per cent in those without cardiac disease (p = 0.032). Smoking was associated with a 10.6 per cent rate of significant disease compared with a 2.3 per cent rate in nonsmokers (p = 0.065). Hypertension and diabetes were not significant risk factors. Significant stenosis of the carotid artery was found in seven of 40 patients in whom coronary arterial disease, peripheral vascular disease and smoking were all present.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Preferential use of EPTFE for above-knee femoropopliteal bypass grafts.

We have used polytetrafluoroethylene preferentially for bypasses to the above-knee popliteal artery since 1979. Since this approach has recently been challenged, we reviewed our experience with 138 grafts in 128 patients. The majority (74%) of patients were male with a mean age of 63.2 years. Risk factors included: smoking (85%), hypertension (55%), diabetes mellitus (45%), and coronary artery disease (41%). The indications for operation were disabling claudication (18%), rest pain (42%), gangrene/tissue loss (33%), and miscellaneous (7%). Perioperative (30 day) mortality was 3% and morbidity (excluding amputation or graft failure) was 5%. Patients were followed for up to eight years with a mean follow-up of 22.1 months. Grafts which remained patent, but did not prevent major amputation, were classified as "failed". Primary patency was 75% at one year and 54% at five years. Limb salvage was 88% at one year and 70% at five years. Risk factors, indication for operation and arteriographic runoff had no statistically significant impact on short- or long-term patency. However, bypass grafts to isolated popliteal segments had a significantly (p = 0.025) increased perioperative failure rate compared to all other grafts. Our data support the continued use of polytetrafluoroethylene for above-knee femoropopliteal bypass except perhaps in patients who require grafting to an isolated popliteal segment where higher early failure rates were seen.

Aged↗
PubMed1990

Is the continued use of ocular pneumoplethysmography necessary for the diagnosis of cerebrovascular disease?

The combination of duplex scanning and ocular pneumoplethysmography (OPG) has been used by many vascular laboratories for noninvasive evaluation of the carotid arteries. This study was undertaken to determine if OPG significantly improved the accuracy of duplex scanning alone. Three hundred eighty-five carotid arteries were studied in 190 patients with angiograms, duplex scans, or OPG. A total of 329 carotid arteries were examined with all three modalities. Three different criteria were used to interpret the OPG results, one each intended to deliver a high sensitivity, specificity, and overall accuracy. Depending on the criteria used, sensitivity of OPG alone for detecting hemodynamically significant (greater than 50%) stenosis ranged from 53% to 83%, with a specificity of 59% to 94%. Duplex scanning alone had a sensitivity of 87% and a specificity of 90% for similar lesions. If patients with only intracranial arterial stenosis were excluded, the sensitivity of the duplex scan rose to 91%. The addition of OPG to the duplex scan slightly increased sensitivity (range 91% to 95%; difference not significant) but significantly decreased specificity (range 56% to 84%; p less than 0.005). For detecting stenoses greater than 80%, the duplex scan alone had a sensitivity of 90% and a specificity of 88%. The addition of OPG to duplex scanning slightly increased sensitivity for these high-grade lesions but significantly decreased specificity (p less than 0.001) and overall accuracy. These results were unaffected by the presence or absence of intracranial disease. Because the addition of OPG to duplex scanning reduces specificity and accuracy without any significant increase in sensitivity, we no longer use it as part of our routine noninvasive cerebrovascular examination.

Carotid Arteries↗
PubMed1990

Repositioning of partially dislodged Greenfield filters from the right atrium by use of a tip deflection wire.

Dislodgement of a Greenfield filter in the right atrium is one of the most serious complications of this procedure. Retrieval of such a misplaced filter may require surgical intervention by means of cardiopulmonary bypass surgery, which is very hazardous in these often severely ill patients. We describe two cases in which the filter became partially dislodged from its carrier in the right atrium. We were able to successfully reposition the filter by using a tip deflection wire, thereby obviating the need for an open cardiac procedure.

Adult↗
PubMed1990

Femur fracture with limb shortening causing occlusion of a polytetrafluoroethylene femoral popliteal graft.

Traumatic occlusion of lower extremity polytetrafluoroethylene arterial grafts is exceedingly rare. We report a patient who suffered a supracondylar femur fracture resulting in shortening of her right lower extremity with kinking and thrombosis of her above-knee polytetrafluoroethylene arterial graft. This is the first report in the English language of prosthetic graft occlusion as a result of traumatic limb shortening. The graft thrombus was successfully lysed by use of intraarterial urokinase, and the kink was repaired by graft resection and reanastomosis. The mechanism of injury and treatment are discussed.

Angiography↗
PubMed1989

A comparison between fibronectin and Matrigel pretreated ePTFE vascular grafts.

Two distinct series of experiments were performed to compare the behavior of ePTFE vascular grafts coated with basement membrane gel to that of identical grafts coated with fibronectin. Bilateral carotid interposition grafts (10 cm long) were interposed in 16 conditioned mongrel dogs. In the first series of experiments (n = 10), each graft was seeded with radiolabeled endothelial cells and initial endothelial cell adherence was determined. Following restoration of blood flow in the grafts, endothelial cell retention was measured for 24 hours. Seeding efficiency was 66.48% (+/- 13.2) for fibronectin-coated grafts and 56.58% (+/- 13.51) for gel-coated grafts. There was a slow, constant loss of activity during the first 90 minutes of imaging, and at 24 hours of observation the activity remaining on the fibronectin-coated graft was 13.2 +/- 3.98% of the initial graft activity. Although the basement membrane gel had a higher mean activity at 24 hours (18.9 +/- 7.22%), the difference was not statistically significant at any interval. In the second series of animals (n = 6), radiolabeled platelets were injected within 60 minutes following restoration of flow. Total platelet activity on the explanted grafts was 3.36 (+/- 1.35) x 10(5) counts per gram/0.2 minute for the fibronectin-coated grafts. The gel-coated grafts had 2.74 (+/- 1.33) x 10(5) counts per gram/0.2 minute, a difference that was not statistically significant. Thus, despite its theoretical appeal, basement membrane gel was no better than fibronectin in increasing endothelial cell adherence and retention, and the resulting flow surface of grafts treated with either compound appeared to attract platelets to an equal degree.

Animals↗
PubMed1989

Functional failure of patent femorodistal in situ grafts.

We have treated several patients who required major, proximal extremity amputations despite a patent infrainguinal in situ saphenous vein bypass graft. To determine those factors predisposing to such paradoxical limb loss, we studied a group of 45 patients who underwent 48 in situ, femorodistal bypass grafts for tissue necrosis and who maintained a patent graft throughout the perioperative period. Within this cohort, we compared two distinct subgroups: Group I, whose limbs (n = 8) ultimately required a major proximal amputation; Group II, whose limbs (n = 40) emerged with a viable foot and did not require a major amputation. There was no significant difference in the incidence of diabetes, renal failure, smoking, or postoperative ankle/brachial index between the two groups. The presence of gangrene (88% vs 45%), invasive sepsis (63% vs 23%), and combined gangrene and sepsis (63% vs 18%) was significantly (p less than 0.05) more prevalent in Group I versus Group II. Forty-three percent of patients with both gangrene and foot sepsis required a major proximal amputation despite a patent graft. Such patients are at high risk for limb loss even if they undergo successful revascularization.

Aged↗
PubMed1989

The potential unreliability of indium 111 oxine labeling in studies of endothelial cell kinetics.

The current widespread use of indium 111 oxine for labeling endothelial cells to study their interaction with various bioprosthetic flow surfaces presupposes a high retention of the radioisotope within the cell and a lack of significant adherence of any marker released from the cell to the surface under study. We measured the loss of indium 111 from freshly harvested, canine, venous endothelial cells, and their viability in cell culture, for varying intervals up to 24 hours. At prescribed intervals, aliquots of the radiolabeled endothelial cell suspension were centrifuged, and the supernatant was separated from the cell pellet. The relative radioactivity of each was measured in a gamma well counter and the spontaneous loss of marker from the endothelial cells was calculated. Spontaneous loss of indium 111 was 7.8% +/- 1.9% at 1 hour and 47.6% +/- 1.8% at 24 hours. Loss of activity was virtually constant between 14 and 24 hours. Endothelial cell viability was 80% at 24 hours. We next studied the in vitro affinity of indium 111 oxine and indium 111 transferrin for untreated expanded polytetrafluoroethylene vascular grafts and for similar grafts treated with two surfactants commonly used to increase the "wetability" of expanded polytetrafluoroethylene, a nonionic sufectant (Nonidet) and tridodecylmethylammonium chloride, and with two glycoproteins, fibronectin and basement membrane gel. A minimum of three graft segments were studied in each group. The affinity of graft material for indium 111, in both its oxine and transferrin complex, was significantly increased by treating the graft with a wetting agent, and it was further increased by the addition of a glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The limitations of impedance plethysmography in the diagnosis of acute deep venous thrombosis.

We reviewed our experience with impedance plethysmography (IPG) and duplex scanning in the diagnosis of acute deep venous thrombosis (DVT) to determine their respective accuracy and current role in our noninvasive vascular laboratory. During a recent 22-month period 1776 patients were evaluated in our laboratory for DVT. Sixty patients (64 limbs) underwent ascending venography within 48 hours of testing (49 limbs were evaluated by all three modalities). With the venograms used as the reference standard, B-mode scanning correctly identified the presence of acute thrombus in 24 of 27 limbs (88.8%) and the absence of thrombus in 31 of 34 limbs (91.2%), for an overall accuracy of 90.6%. IPG alone was less sensitive (75%) and less specific (44.8%), with an overall accuracy of only 57.1%. Twenty-eight IPGs were performed on patients with negative venous scans. Two positive IPGs were the result of chronic venous occlusion and two others detected clinically significant isolated iliac vein thrombi, but 13 patients had false positive IPGs. One false negative IPG occurred. The difference in the sensitivity of scan alone vs scan plus IPG was not significant (chi 2 = 0.045; difference not significant), but the decrease in specificity was chi 2 = 17.3; p less than 0.001). The rarity of isolated iliac vein thrombosis and the high false positive rate for IPG do not justify its continued use if B-mode venous scanning is available. Although positive scan results may be used confidently to institute therapy without the need for venography, in high-risk patients with a strong clinical suspicion of proximal DVT despite a negative scan venography should be obtained before withholding anticoagulation.

Acute Disease↗
PubMed1989

Are routine inferior vena cavograms necessary before Greenfield filter placement?

In August 1983 we began routinely studying the inferior vena cava (IVC) before placement of a Greenfield filter. We have performed 83 caval interruptions since that time, but six patients were excluded from this study because an IVC clip had been placed in three patients during other abdominal surgery, and the medical records of three others could not be retrieved. Of the remaining 77 patients, 65 (84%) had IVC venograms taken before placement of their filter. We personally reviewed 63 of these cavograms but had to accept the radiologist's reports for two studies that could not be retrieved. Ten (15%) cavograms showed abnormalities that significantly affected the placement of the filter. The most frequent abnormality was intracaval clot extending above the L3-4 interspace. Other important abnormalities were severe narrowing of the diaphragmatic IVC (two patients) and a tortuous IVC in a patient with severe scliosis. Seven (11%) additional cavograms showed unilateral iliac thrombus that would have influenced the surgical approach had a femoral approach been required. Formal preoperative cavography expedited filter placement and reduced operating time by obviating the need for intraoperative angiograms. Because 26% of the cavograms showed clinically important information, we recommend that routine IVC angiograms be taken before filter placement.

Evaluation Studies as Topic↗
PubMed1989

A simple method for preventing blood-borne contamination to operating room personnel during vascular reconstructive operations.

Although the risk of infection with hepatitis or HIV remains low, and the effectiveness of steps to reduce even this small risk is difficult to assess, the sequelae of the infection with either virus are often devastating. We described herein the use of a sterile Petri dish to inspect vascular anastomoses during arterial reconstructive operations. This simple, inexpensive precaution has been in use at the University of Cincinnati for two years and has proved so effective in preventing the contamination of operating room personnel with blood from a patient that it has recently become a routine part of all vascular reconstructive operations.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Bacterial infectibility of chronically implanted endothelial cell-seeded expanded polytetrafluoroethylene vascular grafts.

Vascular prosthetic grafts become more resistant to infection as the interval between implantation and bacteremic challenge increases. Endothelial cell (EC) seeding of such grafts has been shown to improve measurably their ability to resist a bacteremic challenge several weeks after implantation, presumably by reducing the amount of thrombus-free area (TFA) on their luminal surface. However, no investigators have reported the impact of EC seeding on the ability of chronically implanted vascular prostheses to resist a late bacteremic challenge. Bilateral common carotid interposition grafts were placed in 15 adult mongrel dogs with a 4 mm internal diameter, experimental, expanded polytetrafluoroethylene (ePTFE) prosthesis. One animal died shortly after operation and the grafts in two dogs thrombosed, thereby leaving 12 animals with at least one patent graft for subsequent study. At a mean interval of 45 weeks after implantation, five dogs (seven patent grafts) were challenged with an intravenous infusion of 3 X 10(8) radiolabeled Staphylococcus aureus; bacterial adherence and the TFA of the graft's luminal surface were determined for each of the patent grafts. There was no statistically significant difference in bacterial adherence or TFA between EC-seeded and control grafts. At a mean interval of 53 weeks after implantation, the remaining seven dogs (14 patent grafts) received a similar bacterial infusion and the animals were allowed to recover. Five days later, the grafts were harvested and cultured. Once again, there was no significant difference in the infectibility of EC-seeded vs. control grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Use of autologous spiral vein grafts for vascular reconstructions in contaminated fields.

Vascular reconstructions in heavily contaminated fields can be particularly challenging. Prosthetic grafts are rarely suitable because of the risk of infection, but the saphenous vein is usually too small for isodiametric replacement of large arteries and veins. Although surgeons rarely consider the use of spiral vein grafts, they may occasionally be the ideal autogenous vascular replacement because they can be tailored to fit a vessel of any size. We report the use of spiral vein grafts in three patients requiring vascular reconstructions in the presence of heavy bacterial contamination.

Adolescent↗