Sequence conservation in field and experimental isolates of Borna disease virus

Coding and noncoding sequences were analyzed from field and experimental isolates of Borna disease virus. For a 24-kDa protein, maximum divergence was 1.5% at the predicted amino acid level and 3.1% at the nucleotide level. For a 40-kDa protein, maximum divergence was 1.1% at the predicted amino acid level and 4.1% at the nucleotide level. The highest variability in sequence (10%) was found in a 40-nucleotide stretch of genomic RNA between coding sequences for the 40- and 24-kDa proteins. The degree of sequence conservation in these isolates, passaged in various host species in vivo and in vitro over a period of 64 years, is unusual for negative-strand RNA viruses.

Influence of variability of interpretation of contrast venography for screening of postoperative deep venous thrombosis on the results of a thromboprophylactic study

To assess interobserver variability of venography for screening for postoperative deep venous thrombosis (DVT), we used 185 bilateral ascending contrast venograms (366 lower limbs) which were performed using the long-leg film technique, in the frame of a trial of the efficacy of two low-molecular-weight-heparin fractions (initial evaluation). These venograms were submitted in a multicenter setting to three further readers who performed a serial scoring as DVT, no DVT or non-evaluable. DVTs were diagnosed in 78, 55 and 59/366 limbs (initial evaluation: 58). The proximal locations of DVTs were 16, 9 and 16 (initial evaluation: 15) and the non evaluable limbs 3, 5 and 18 (initial evaluation: 0). Apparent pairwise agreement between the three readers ranged from 87 to 90% (true coefficient of agreement Kappa 0.63-0.70). It ranged from 89 to 93% (Kappa 0.63-0.74) for the comparison between the readers and the initial evaluation. This considerable degree of disagreement among experienced readers should be taken into account in calculating sample sizes in prospective thromboprophylactic studies. Indeed, one of the two prophylactic regimens proved to be significantly (p = 0.012, p = 0.031, p = 0.049) or non-significantly (p = 0.073) superior to the other one depending upon the reading of venograms.

Allograft vein bypass: is it an acceptable alternative for infrapopliteal revascularization?

PURPOSE

Autogenous vein bypass grafts to infrapopliteal outflow sites have patency and limb salvage rates significantly superior to those obtained with prosthetic grafts. However, when infrageniculate bypass is required for limb-threatening ischemia in the patient lacking suitable autogenous veins, nonautogenous reconstruction or primary amputation are the only other alternatives.

METHODS

During a 2-year period we implanted 25 cryopreserved allograft saphenous vein bypass grafts in 24 patients (median age 76 years) with tissue necrosis (20 patients), rest pain (4 patients), or acute ischemia (1 patient); 16 patients were men and 8 were women. As many as six previous revascularizations were performed in 79%; two grafts extended to the infrageniculate popliteal artery; 23 grafts extended to a paramalleolar vessel.

RESULTS

Secondary patency at 1 month was 87%, but only 36% at 1 year. Use of warfarin (Coumadin) failed to improve the patency rate (five of nine occlusions treated with Coumadin versus eight of 16 not treated with Coumadin). Only eight of 24 patients are alive with open grafts; nine patients have died.

CONCLUSIONS

Unheralded occlusions more typical of prosthetic graft failure tempered the initial enthusiasm and effectiveness of vein allografts. All autogenous options must be exhausted to complete distal, secondary revascularization before resorting to nonautogenous conduits. Use of allograft veins must be viewed with continued skepticism.

Lasting safe interruption of endarterectomy thrombosis by transiently infused antithrombin peptide D-Phe-Pro-ArgCH2Cl in baboons

To evaluate the relative antithrombotic efficacy and hemostatic safety of antithrombin therapy for vascular thrombus formation at sites of mechanical vascular injury, we administered the potent and specific irreversible synthetic antithrombin D-PHE-PRO-ARG chloromethyl ketone (D-FPRCH2Cl) after performing carotid endarterectomies in baboons. The continuous intravenous infusion of D-FPRCH2Cl, 100 nmol/kg per minute for 1 hour, abolished acute carotid endarterectomy thrombosis for at least 48 hours. The plasma level of D-FPRCH2Cl during the infusion was maintained steady at 7.2 +/- 0.9 mumol/L, but decreased rapidly after discontinuing its infusion (T50 17 minutes). Platelet deposition, measured in real time using autologous 111In-platelet scintillation camera imaging, was 1.51 +/- 0.40 x 10(8) platelet/cm in the 14 treated animals 90 minutes postoperatively, compared with 11.7 +/- 1.16 x 10(8) platelet/cm in 14 heparin-treated controls (P < .002). The antithrombotic benefit was equivalent for treatment begun either 5 minutes before (nine animals) or 15 minutes after (five animals) reestablishing flow in the operated vessel, ie, 1.59 +/- 0.36 x 10(8) platelet/cm versus 1.35 +/- 0.51 x 10(8) platelet/min, respectively; P > .5. Endarterectomy thrombosis remained decreased for at least 48 hours postoperatively, as determined by the ratio between net 111In-platelet radioactivity at the endarterectomized site versus whole blood (ratio 0.82 +/- 0.25 in the treatment group v 3.03 +/- 0.51 in heparin controls at 90 minutes, P < .005; and 0.85 +/- 0.23 v 3.25 +/- 0.48 at 48 hours, P < .002). The marked reduction in endarterectomy thrombosis in treated animals at 48 hours was confirmed by scanning electron microscopy. Thrombin activity formed rapidly and became immediately bound to thrombus on thrombogenic segments in untreated control studies; treatment with D-FPRCH2Cl irreversibly inactivated the thrombus-bound thrombin. Hemostatic function, as measured by bleeding time (BT), activated partial thromboplastin time (APTT), and prothrombin time (PT) was impaired throughout the intravenous administration of D-FPRCH2Cl (BT > 30 minutes, APTT > 150 seconds, PT > 50 seconds); BT, APTT, and PT values were normal 30 minutes after discontinuing the infusions. As expected, blood loss into the surgical wound was substantial in nine animals receiving therapy initiated before restoring flow in the operated vessel (mean 95 mL, range 45 to 130 mL). By contrast, beginning D-FPRCH2Cl therapy in five animals 15 minutes after restoring arterial flow, a time when surgical hemostasis had been achieved, prevented excessive blood loss (mean 15 mL, range 10 to 35 mL; P < .01 compared with earlier treatment) without compromising the antithrombotic effects.(ABSTRACT TRUNCATED AT 400 WORDS)

Unexpectedly high rate of phlebographic deep venous thrombosis following elective general abdominal surgery among patients given prophylaxis with low-molecular-weight heparin

One hundred ninety-four patients undergoing elective general abdominal surgery were randomized in a single-blind study to receive one daily subcutaneous injection of a low-molecular-weight heparin, dalteparin sodium (2500 IU, n = 97) or nadroparin calcium (3075 IU, n = 97), two regimens that are approved in Europe to prevent deep venous thrombosis. On the eight postoperative day, bilateral ascending leg phlebography (n = 185) showed the presence of deep venous thrombosis in 45 cases (24.3%; 95% confidence interval, 18% to 31%), with a significantly higher rate (on intention-to-treat) among the patients who received the lower dosage (30 vs 15 deep venous thromboses). We conclude that the two regimens of low-molecular-weight heparin that were used in this study failed to prevent postoperative phlebographically proved deep venous thrombosis in one of four patients.

Venography of the lower limbs. Pitfalls of the diagnostic standard. The ETTT Trial Investigators

RATIONALE AND OBJECTIVES

Phlebography is considered the diagnostic standard for suspected deep venous thrombosis. The authors studied the inter-observer variability of phlebogram interpretation in the setting of a multicenter therapeutic trial of the thrombolytic agent alteplase.

METHODS

The interpretation of 31 pairs of venograms (before and after thrombolytic therapy) was studied by comparing the quantitative Marder's scores which were computed by three experts and the qualitative assessment of phlebographic changes induced by thrombolysis by the panel of experts and by the investigators.

RESULTS

Although the scores of the three experts correlated fairly well (r = .67-.82; P < .001), they differed significantly from each other (P < .0001). Substantial differences also were found between local (by investigators) qualitative evaluation of the venographic changes induced by the treatment and central evaluation by the panel of experts (coefficient of agreement kappa = 0.19), local assessment being significantly more optimistic (P = .002) than central judgment.

CONCLUSION

Significant differences were observed between assessment of changes in venographic scores after thrombolytic treatment both among three expert radiologists, and between the panel of experts and the local investigators of the multicenter trial. This observation points to the need for an a priori definition of well-characterized decision criteria to allow a valid interpretation of the effects of the therapeutic intervention.

Circumferential venolysis and paraclavicular thoracic outlet decompression for "effort thrombosis" of the subclavian vein

Effort thrombosis of the subclavian vein (Paget-Schroetter syndrome) has long been considered a primary thrombotic process, but recent experience suggests that it may commonly result from repeated mechanical compression. Increased awareness of the pathophysiology of this syndrome can allow timely, improved diagnostic screening and the use of specific surgical intervention to relieve the venous consequences. During the past 15 years we have treated six patients with mechanical compression in the thoracic outlet causing surgically correctable venous occlusive problems. There were four men and two women with an average age of 38 years (range 26 to 53 years). All patients exhibited pain, swelling, and cyanosis of the upper extremity, with worsening venous congestion on abduction of the arm. Five of six patients were originally treated for effort thrombosis of the subclavian vein with arm elevation and anticoagulation; two also underwent immediate thrombolytic therapy with urokinase. Venography was prompted in each case by positional symptoms during follow-up and showed irregular stenosis of the subclavian vein adjacent to the first rib. All patients underwent extended first rib resection and circumferential venolysis (one patient underwent bilateral procedures); one was performed through a transaxillary approach, two through a supraclavicular approach, and four through a new, "paraclavicular" approach. All subclavian veins appeared normal after venolysis. Five of six patients also underwent complete scalenectomy and brachial plexus neurolysis. In each patient, venous and neurogenic symptoms resolved and venography confirmed a patent subclavian vein, with follow-up ranging from 11 months to 13 years (mean 3.8 years).

Transluminal angioplasty of the aorta, renal and mesenteric arteries in Takayasu arteritis: Report of two cases

Two patients with Takayasu arteritis presented with either severe renovascular hypertension or profound weight loss due to intestinal angina. The leading clinical signs were cured by successful percutaneous transluminal angioplasty (PTA) of the abdominal aorta and renal arteries in one patient and of the superior mesenteric artery and coeliac trunk in the second. These results and a literature review of the topic suggest that PTA should be the first therapeutic approach in symptomatic arterial stenoses due to TA in the inactive stage of the disease.

Value of liquid crystal contact thermography and plasma level of D-dimer for screening of deep venous thrombosis following general abdominal surgery

Because the use of radioactive fibrinogen uptake test (FUT) has become questionable both for ethical (risk of virus transmission) and technical (lack of sensitivity) reasons, we investigated the potential value of two alternative methods for screening of asymptomatic deep venous thrombosis following elective digestive surgery: liquid crystal contact thermography (LCCT) and measurement of plasma concentration of D-dimer (DD), as compared with bilateral ascending phlebography. Out of 194 patients, 185 underwent phlebography on the 8th (0-19, median and range) postoperative day. Despite prophylaxis with low-molecular-weight heparin and elastic stockings, DVT was detected on phlebography in 58 legs of 45 patients. Sensitivity of LCCT with respect to the presence of DVT was 55% (n = 184 patients) or 28% (n = 368 legs) with a specificity of 67% and 82%, respectively. These poor performances were obtained despite a good interobserver agreement for the LCCT assessments (overall kappa coefficient of 0.66 between three experts). The most accurate cut-off of DD for discriminating patients with or without DVT was 3,000 micrograms/l, as determined by ROC curve analysis. Sensitivity of a DD level of more than 3,000 micrograms/l for the presence of phlebographically documented DVT on the 8th postoperative day was 89% for a specificity of 48%. Thus, LCCT cannot be used for screening of postoperative, mainly asymptomatic DVT following general surgery. On the other hand, measurement of plasma DD may be useful for initial screening, a negative result (level less than 3,000 micrograms/l) allowing to exclude DVT (negative predictive value of 93%) and a positive result (positive predictive value of 35%) requiring confirmation by phlebography.(ABSTRACT TRUNCATED AT 250 WORDS)

Preservation of arm veins for arterial reconstruction

The results of surgery for lower extremity salvage have improved steadily over the past decade. One of the principles accounting for this advance is the preferential use of autogenous veins for peripheral bypass surgery. Nonautogenous and prosthetic grafts to the infrageniculate (below knee) level have patency rates significantly lower than autogenous bypasses. Currently, the technical limits of bypass surgery often depend upon the availability of adequate venous conduits. The saphenous vein has been the conduit of choice for distal arterial bypasses. However, some patients lack saphenous veins as a result of previous vein harvesting for coronary or other arterial surgery, phlebitis, variations in venous anatomy, previous vein stripping, or other conditions. In these patients, arm veins (cephalic and basilic) have been used successfully for limb salvage. There are several requirements for the successful use of arm veins. These include a detailed knowledge of the anatomy of the cephalic and basilic veins, education of patients and health care professionals, nursing protocols to preserve arm veins, and the training of surgical nurses in the demanding technical maneuvers for arm vein implantation. This paper will address these subjects.

Outpatient percutaneous transluminal angioplasty for peripheral arterial disease

OBJECTIVES

Percutaneous transluminal angioplasty (PTA) of peripheral arterial stenoses or occlusions has become a widely recognized therapy in patients with disabling arterial insufficiency of the lower limbs. In most institutions, the procedure requires a two-day hospital stay, and official guidelines do not recommend ambulatory practice. Therefore, we reviewed our experience with outpatient PTA from 1986 through 1991.

METHODS

PTA was performed in an outpatient setting in 141 subjects suffering from peripheral arterial insufficiency (mostly intermittent claudication), which represents 51% of the peripheral PTAs performed in our institution during this period (n = 276).

RESULTS

Immediate technical success was achieved in 127 (90%), resulting in 112 (79%) with clinical improvement at 10 days. Complications were recorded in 21 (15%) procedures, most of them being minor (n = 14, 10%). Fourteen patients (10%) required prolonged observation. None of the major complications (n = 7, 5%) and only one (0.7%) (groin haematoma with one-day hospital stay) of the minor side effects were attributed to the ambulatory aspect of the procedure.

CONCLUSIONS

Outpatient PTA may be performed in selected patients suffering from symptoms of peripheral arterial disease without additional risk.

Isolated thigh claudication as a result of fibromuscular dysplasia of the deep femoral artery

Isolated thigh claudication as a result of fibromuscular dysplasia of the deep femoral artery has not previously been reported. This case report describes a patient with fibromuscular dysplasia of the carotid arteries in whom progressive unilateral thigh claudication developed despite normal femoral pulses. Deep femoral artery occlusion caused by fibromuscular dysplasia was successfully treated by common femoral to distal deep femoral artery bypass. Fibromuscular dysplasia of the infrainguinal arteries is rare but should be included as a possible cause of lower extremity ischemic symptoms.

Double-blind, randomized comparison of systemic continuous infusion of 0.25 versus 0.50 mg/kg/24 h of alteplase over 3 to 7 days for treatment of deep venous thrombosis in heparinized patients: results of the European Thrombolysis with rt-PA in Venous Thrombosis (ETTT) trial

Thirty-two patients with acute, proximal-vein thrombosis were treated with heparin and alteplase (0.25 versus 0.5 mg/kg/24 h during 3-7 days) in a randomized, double-blind, multicenter, European (ETTT) trial. The treatment resulted in a decrease of the venographic Marder's score from 18 (6-25) to 13 (2-24) units (median, range) in Group I (0.25 mg/kg/24 h, n = 15, median decrease 3.0, p = 0.32) and from 17.5 (3-33) to 15.5 (0-27) in Group II (0.5 mg/kg/24 h, n = 16, median decrease 4.0, p = 0.23). Comparison of the sequential venograms could be performed in 14 cases of Group I and in 15 cases in Group II. A minority of patients showed substantial partial recanalization of the initially obstructed veins on the control venogram (one in each treatment group) and most of the control venograms showed either thrombus size reductions (5 in Group I, 7 in Group II) or no change or even deterioration (8 in Group I, 7 in Group II). Major bleedings were observed in 7 patients (7/32, 22%), 5 of them occurring in Group II (5/17, 29%). Thus, the results of the ETTT trial show that the used low dosages of alteplase administered intravenously over 3-7 days in heparinized patients cannot be recommended as a treatment for patients with deep venous thrombosis of lower limbs and/or pelvis. Further studies are needed to define a more suitable dosage regimen of alteplase in this indication.

Chronic visceral ischemia. Three decades of progress

Symptomatic visceral atherosclerosis is a major surgical challenge because of its life-threatening course and the complexity of its definitive operative treatment. Evolution in the operative approach to the visceral aorta and progress in the intraoperative management of patients undergoing complex vascular reconstructions prompted a review of the authors' cumulative experience in the surgical management of chronic visceral ischemia. Among all patients undergoing visceral revascularization at the University of California, San Francisco during the past three decades, 74 patients were identified whose primary reconstruction used transaortic endarterectomy (TA TEA) (n = 48) or antegrade bypass (AB) (n = 26), the authors' preferred revascularization techniques. The two treatment groups were comparable in gender distribution, age, presenting symptoms, and physical findings, although the amount of preoperative weight loss was greater in the AB group (35.8 +/- 19.5 versus 22.4 +/- 12.0, p = 0.003). The groups were also comparable in the prevalence of atherosclerosis risk factors, symptomatic vascular disease at other sites, and previous vascular operations. However associated renal artery atherosclerosis was slightly greater in the TA TEA group (58.3% versus 23.1%, p = 0.07) when compared to the AB group. Antegrade bypass was usually performed transabdominally (88.5%), while TA TEA was approached thoracoretroperitoneally (75.0%). Celiac revascularization was almost universal in both treatment groups, but the TA TEA group underwent significantly more frequent superior mesenteric artery (SMA) revascularization (93.8% versus 46.2%, p = 0.0001) and slightly more frequent inferior mesenteric repair (18.8% versus 3.8%, p = 0.07) than the AB group. In addition the frequency of combined renal and visceral repair (25.0% versus 0.0%, p = 0.01) as well as combined aortic, renal, and visceral repair (22.9% versus 3.8%, p = 0.03) was significantly greater in the TA TEA group. The obligatory interval of renal and visceral ischemia did not differ between the two approaches. The perioperative mortality rate was 12.2% and was the same for TA TEA (14.6%) and AB (7.7%). Overall the incidence of complications was the same with either operative approach, although patients in the TA TEA group tended to have multiple complications (17.1% versus 0.0, p = 0.03) and all significant pulmonary complications occurred in this group. Two patients were lost to follow-up. The cumulative percentage of patients who remained asymptomatic following AB or TA TEA was (respectively) 95.8% and 97.3% at 1 year and 86.5% and 86.1% at 5 years. Both of these operative approaches provide durable symptom relief with acceptable operative morbidity and mortality rates.(ABSTRACT TRUNCATED AT 400 WORDS)

Measurement of D-dimer in plasma as diagnostic aid in suspected pulmonary embolism

The potential of plasma measurement of D-dimer (DD), a specific derivative of crosslinked fibrin, for diagnosis or exclusion of pulmonary embolism was investigated in a prospective series of 171 consecutive patients who attended an emergency department with suspected pulmonary embolism. The diagnosis was made or excluded by means of a clinical decision-making process which included clinical evaluation, ventilation-perfusion (VQ) lung scan, and, as indicated, pulmonary angiography, venography, or non-invasive examination of the leg veins. Pulmonary embolism was diagnosed by this process in 55 (32%) of 170 patients with sufficient data. All but 1 of these 55 patients had a DD concentration of 500 micrograms/l or above. The sensitivity and specificity of this cutoff concentration for the presence of pulmonary embolism were 98% and 39%, respectively, which give positive and negative predictive values of 44% and 98%. Among the 115 patients (68%) who had inconclusive VQ scans, 31 were diagnosed as having pulmonary embolism. 29 of the remaining 84 patients without pulmonary embolism had DD concentrations below 500 micrograms/l, which means that further diagnostic procedures could have been avoided in a quarter of the patients with inconclusive VQ scans. The sensitivity of the plasma measurement of DD remained high even 3 and 7 days after presentation (96% and 93%). Plasma measurement of DD therefore has a definite place in the diagnostic procedure for suspected acute pulmonary embolism in attenders at emergency departments: a concentration below 500 micrograms/l rules out the diagnosis.

Noninvasive assessment of cerebral collateral blood supply through the ophthalmic artery

We assessed the potential of 2-MHz pulsed-wave transorbital Doppler ultrasonography to delineate the role of the ophthalmic artery as a source of collateral cerebral blood supply by comparing oculopneumoplethysmography, transorbital Doppler ultrasonography, periorbital continuous-wave Doppler ultrasonography, and transcranial Doppler ultrasonography in 25 patients with unilateral internal carotid artery occlusion and five controls with 10 normal internal carotid arteries. Systolic ophthalmic artery blood velocity was reduced ipsilateral to an internal carotid artery occlusion (38.2 +/- 10.2 cm/sec) compared with the contralateral and control velocities (46.0 +/- 10.3 and 47.5 +/- 6.8 cm/sec, respectively; p less than 0.05). Ophthalmic systolic pressure measured by oculopneumoplethysmography was 94.7 +/- 13.2 mm Hg ipsilateral to an internal carotid artery occlusion compared with 108.4 +/- 15.3 mm Hg on the contralateral side (p less than 0.01). Transorbital and periorbital Doppler ultrasonography detected reversed ophthalmic artery blood flow ipsilateral to an internal carotid artery occlusion in 44.0% and 40.0% of the patients, respectively. Systolic middle cerebral artery blood velocity was 55.2 +/- 22.3 cm/sec ipsilateral to an internal carotid artery occlusion compared with 79.4 +/- 23.5 cm/sec on the contralateral side (p less than 0.05) and 101.2 +/- 18.9 cm/sec in the controls (p less than 0.05). Reversed ophthalmic artery blood flow was associated with a low middle cerebral artery blood velocity and lack of major intracerebral collaterals. Transorbital Doppler ultrasonography permits noninvasive evaluation of the ophthalmic artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-up after partial interruption of the vena cava with the Günther filter

We have treated 34 patients with the Günther filter. Follow-up ranged from 5 to 891 days (median 129). Eight patients died 5-352 days (median 26) after filter insertion, without relation to the procedure. Six of them had extensive cancer. At 2 weeks, a mean caudal migration of 27 +/- 20 mm of the Günther filter was observed (n = 24). No significant migration occurred later than 2 weeks. In 2 patients, downward displacement of the device to the iliocaval junction was observed, with recurrent embolism in 1 case. A second filter was placed in the infrarenal vena cava in both cases. There was no other recurrent embolism and no sign of vena caval occlusion.

Multiple site estimates of erythropoietin and renin in polycythemic kidney transplant patients

The development of polycythemia after renal transplantation is a well known phenomenon and its etiology remains controversial. In particular, it is unknown whether inappropriate erythropoietin (EPO) production could be a reason. Utilizing a sensitive radioimmunoassay for EPO we have measured EPO concentrations in venous blood from native and grafted kidneys in three normocythemic and seven polycythemic patients. We found that (1) in our posttransplantation polycythemic patients there are inappropriately high systemic EPO levels, hence that posttransplantation polycythemia is related to EPO overproduction. (2) This high EPO production comes from the native kidneys. (3) There is a correlation between EPO and renin levels in the peripheral as well as in native and transplanted kidneys' venous samples.

Plasma D-dimer in suspected pulmonary embolism: a comparison with pulmonary angiography and ventilation--perfusion scintigraphy

The diagnosis of pulmonary embolism remains a difficult issue. In a previous study of patients submitted to ventilation--perfusion (V-P) scintigraphy we suggested that measurement of D-dimer might be of value for ruling out the diagnosis of pulmonary embolism if the plasma level was less than 500 micrograms/l (ELISA). In the present paper, this cut-off was validated in a consecutive series of 21 patients who were submitted to pulmonary angiography. Sensitivity and specificity were 100% and 36%, respectively. When these data were pooled with the results obtained following V-P scintigraphy (total number of patients = 67), sensitivity, specificity, and positive and negative predictive values were 100%, 70%, 59% and 100%, respectively. It is therefore worthwhile to further evaluate the value of the plasma measurement of D-dimers, especially in patients with inconclusive lung scintigraphy.

[Liver transplantation. Preliminary results in the district University Hospital of Geneva]

Between July 1987 and May 1989, 11 liver transplants were performed on 10 patients at the University Hospital of Geneva. Of 15 patients evaluated for elective transplantation, 10 were accepted and put on the waiting list. 5 patients were rejected because of a contraindication or because another treatment seemed preferable. 8 transplantations were eventually performed. Emergency transplantation was considered for 6 patients, but could be performed in only 3. Indications for transplantation were as follows: one hepatocellular carcinoma in a non-cirrhotic patient, 2 post-hepatitis cirrhoses (one B and one non-A-, non-B), 3 primary biliary cirrhoses, one autoimmune cirrhosis, one primary sclerosing cholangitis, one cirrhosis on alpha-1-antitrypsin deficiency, and one fulminant B-Delta hepatitis. Most of these patients had advanced liver disease and a limited life expectancy. 8 of the 10 patients transplanted are nevertheless alive and none is hospitalized at the present time. More than mere survival, however, quality of life regained after transplantation prompts us to consider transplantation early in the progress of the disease. Earlier evaluation of patients would make transplantation feasible soon after the first complication of the disease. This attitude would probably prevent patients from dying while on a waiting list and decrease operative as well as early postoperative risks. Better information and coordination regarding potential donors is necessary in Switzerland to obtain better results in organ transplantation.

Healing of polytetrafluoroethylene arterial grafts is influenced by graft porosity

The importance of porosity in synthetic arterial graft healing has not been adequately defined. To determine the effect of porosity on graft healing, we measured the extent of cellular response at late times in 4 mm internal diameter polytetrafluoroethylene grafts of varying porosity (between 10 and 90 microns internodal distance) inserted into the arterial system of baboons. After 1 and 3 months the grafts were retrieved and examined for endothelial coverage, intimal thickening, and endothelial cell and smooth muscle cell proliferation. The pattern of intimal healing with endothelial cells and smooth muscle cells was only related to porosity in the sense that there was an abrupt switch in the pattern of healing as porosity was increased from 30 to 60 microns. In low porosity grafts (10 and 30 microns internodal distances) endothelial coverage of the luminal surface was incomplete and, along with intimal thickening, was limited to graft near the anastomosis. In high porosity grafts (60 and 90 microns internodal distances) luminal endothelial coverage was complete, and intimal thickening was uniformly distributed throughout the graft. The highest porosity graft studied (90 microns) developed areas of focal loss of endothelial cells at late time periods. In this limited series there does appear to be an optimal porosity for polytetrafluoroethylene grafts near 60 microns, since 10 and 30 micron grafts fail to achieve luminal endothelial cell coverage, and 90 micron grafts exhibit instability of the intima with focal endothelial cell loss.

Confluent durable endothelialization of endarterectomized baboon aorta by early attachment of cultured endothelial cells

Since surgical endarterectomy produces a highly thrombogenic vascular flow surface, we evaluated in baboons the capacity of acutely attached, unspread, cultured, homologous aortic endothelial cells to form durable, confluent endothelial cell monolayers and to interrupt acute thrombus formation during exposure to arterial blood flow conditions. When cultured baboon aortic endothelial cells were incubated with segments of freshly endarterectomized baboon aorta for 20 minutes in vitro, 3.8 x 10(5) endothelial cells/cm2 became attached. The endarterectomized surface treated with endothelial cells showed the presence of rounded, unspread endothelial cells with intervening bare areas of vascular media. Platelet deposition onto the endothelial cell--treated surface during exposure to blood under high flow conditions for 1 hour in vivo was markedly reduced by the attached but unspread endothelial cells. Moreover, these attached endothelial cells underwent spreading on the endarterectomized surface in the presence of high shear blood flow to form a confluent endothelial monolayer at the end of 1 hour. Thus acutely attached cultured endothelial cells form a durable thromboresistant monolayer on surgically denuded vascular surfaces during exposure to arterial blood flow.

The natural history of amaurosis fugax with minor degrees of internal carotid artery stenosis

The natural history of amaurosis fugax with hemodynamically insignificant degrees of internal carotid artery stenosis is uncertain. Seventy-three patients over age 40 who presented with amaurosis fugax without obvious cause and had ipsilateral stenoses of 50% or less with carotid duplex scanning were followed for a mean period of 35.5 months (range 3-110) without surgical intervention. At the initial vascular laboratory duplex evaluation, 35 patients had normal arteries (47.9%), 29 had minor (0-19%) stenoses of the ipsilateral internal carotid arteries (39.7%), and 11 had 20-50% stenosis (15.1%). Four patients with 0-19% stenosis and one patient with 20-50% stenosis experienced a subsequent stroke or permanent ipsilateral blindness. When analyzed by life-table format, stroke, blindness, and early death were more frequent in patients with minor degrees of stenosis than in those with normal arteries. Investigations in all patients with amaurosis fugax should be aimed at identifying whether the symptoms are explained by arteriosclerotic, systemic, collagen, cardiac, hematologic, or ophthalmologic disease. When no other etiology is found, and localized carotid bifurcation atherosclerosis of even modest degrees is identified, an atheroembolic etiology should be considered.