CT volume of enhancement of disease (VED) can predict the early response to treatment and overall survival in patients with advanced HCC treated with sorafenib.

OBJECTIVES: To analyse the predictive value of the volume of enhancement of disease (VED), based on the CT arterial enhancement coefficient (ΔArt%), in the evaluation of the sorafenib response in patients with advanced hepatocellular carcinoma (HCC). METHODS: Patients with sorafenib-treated advanced HCC, who underwent a multiphase contrast-enhanced CT before (T0) and after 60-70 days of starting therapy (T1), were included. The same target lesions utilised for the response evaluation according to modified Response Evaluation Criteria in Solid Tumors criteria were retrospectively used for the ΔArt% calculation ([(HUarterial phase - HUunenhanced phase) / HUunenhanced phase] × 100). ΔArt% was weighted for the lesion volume to obtain the VED. We compared VEDT0 and VEDT1 values in patients with clinical benefit (CB) or progressive disease (PD). The impact of VED, ancillary imaging findings, and blood chemistries on survival probability was evaluated. RESULTS: Thirty-two patients (25 men, mean age 65.8 years) analysed between 2012 and 2016 were selected. At T1, 8 patients had CB and 24 had PD. VEDT0 was > 70% in 8/8 CB patients compared with 12/24 PD patients (p = 0.011). Patients with VEDT0 > 70% showed a significantly higher median survival than those with lower VEDT0 (451.5 days vs. 209.5 days, p = 0.032). Patients with VEDT0 > 70% and alpha-fetoproteinT0 ≤ 400 ng/ml had significantly longer survival than all other three combinations. In multivariate analysis, VEDT0 > 70% emerged as the only factor independently associated with survival (p = 0.037). CONCLUSION: In patients with advanced HCC treated with sorafenib, VED is a novel radiologic parameter obtained by contrast-enhanced CT, which could be helpful in selecting patients who are more likely to respond to sorafenib, and with a longer survival. KEY POINTS: • To achieve the best results of treatment with sorafenib in advanced HCC, a strict selection of patients is needed. • New radiologic parameters predictive of the response to sorafenib would be essential. • Volume of enhancement of disease (VED) is a novel radiologic parameter obtained by contrast-enhanced CT, which could be helpful in selecting patients who are more likely to respond to therapy, and with a longer survival.

The pedicled buccal fat pad in oral reconstruction.

AIM: Aim of the study was to present a follow-up on 46 cases in which pedical buccal fat pad (BFP) flaps were used to repair oral defects without any additional local flaps or skin grafts. METHODS: The study comprised 46 patients, 31 men and 15 women, with an age range of 30-78 years (mean age 57.3 years). They were treated with a pedicled flap to repair defects of the ipsilateral maxilla (anterior or posterior), soft palate or retromolar mandibular area following tumor resection, osteonecrosis or the closure of oro-antral fistulae. The defects ranged from 2 × 2.5 cm to 4.5 × 5 cm. All patients were treated under general anesthesia. RESULTS: The flap fully covered the intraoral defect with any aesthetic deficits. After one month, the flap was fully epithelialized and of adequate thickness in all cases. Three postoperative complications were reported: one superficial necrosis and two small fistulae. CONCLUSION: Although the BFP has long been recognized and despite the simplicity of preparing the flap itself, numerically significant reports concerning the use of this technique in reconstructive facial surgery have only recently been published. The pedicled buccal fat flap is convenient and reliably repairs oral defects up to 4.5 cm in diameter on the ipsilateral side of the soft and hard palate, posterior alveolar region of the maxilla and the retromolar mandibular area. The surgical procedure is simple and morbidity at the donor site in not significant.

Edentulous mandible: clinical results of reconstruction with fresh frozen bone.

AIM: The aim of this study was the clinical and radiological evaluation in severe mandibular atrophy (class V-VI Cadwood-Howell) of bone grafts with homologous fresh frozen bone (FFB) in patients with dysesthesia of the inferior alveolar nerve with or without transposition of the NAI in order to perform a proper implant-prosthetic rehabilitation. METHODS: This article presents our experience in mandibular reconstructions performed in 12 patients with severe mandibular atrophy and dysesthesia performing onlay grafts with FFB and subsequent implant-prosthetic rehabilitation. RESULTS: The surgical protocol of homologous bone graft in symptomatic patients with severe mandibular atrophy presented an excellent clinical outcome with disappearance of dysesthesia in all patients treated, good graft integration and a complete implant-prosthetic rehabilitation with loss of only 3 implants at the 24-36 month follow up visit. CONCLUSION: Homologous bone grafting in patients with severe mandibular atrophy may be a viable therapeutic option in cases of prosthetic reconstruction in those symptomatic patients who cannot tolerate removable dentures, reducing intraoperative time, patient morbidity and the complications in common sites of autologous bone graft removal.

[The use of anticoagulant treatment in patients with nonrheumatic atrial fibrillation]. / Utilización del tratamiento anticoagulante en los pacientes con fibrilación auricular no reumática.

INTRODUCTION: The efficacy of anticoagulant treatment in the prevention of thromboembolic complications among patients with nonrheumatic atrial fibrillation is established. In our country, data on the use of this therapy in clinical practice are not available. OBJECTIVE: To examine anticoagulants use among patients with nonrheumatic atrial fibrillation and to analyze the influence of several thromboembolic risk factors in anticoagulant use. PATIENTS AND METHODS: We have studied, 302 patients retrospectively, with nonrheumatic atrial fibrillation. We determined the presence of heart failure, hypertension, previous thromboembolism, diabetes and left atrium dilation. We added age, sex, pattern of non-permanent arrhythmia and hospitalization and we conducted univariate and multivariate analyses to identify their influence the establishment of the anticoagulant treatment. RESULTS: 28.8% of patients were treated with oral anticoagulants, 83.7% were treated with oral anticoagulant or antiplatelet agents. Only three patients, out of 49, aged 80 years or older were treated with anticoagulants. Multivariate analysis showed that previous thromboembolism (odds ratio 4.03 [1.9-8.1]), permanent atrial fibrillation (odds ratio 2.6 [1.3-5.3]), left atrium dilation (odds ratio 2.3 [1.2-4.1]) and heart failure (odds ratio 1.9 [1.07-3.6]) were factors that predicted higher use of anticoagulant treatment. CONCLUSIONS: a) Anticoagulant treatment is underused among patients with nonrheumatic atrial fibrillation; b) previous thromboembolism, left atrium dilation and heart failure have conditioned higher probability of undergoing anticoagulant treatment, and c) patients aged 80 years and over and non permanent atrial fibrillation predicted less use of the therapy.

[Hemorrhagic complications from anticoagulant treatment: analysis of predictive risk factors]. / Complicaciones hemorrágicas del tratamiento anticoagulante: Análisis de factores predictores de riesgo.

UNLABELLED: Anticoagulant therapy has shown its efficacy in the prevention of thromboembolic complications but it is not devoid of bleeding complications. Although the thromboembolic risk of some cardiac diseases may be extrapolated from well-organized clinical trials, the risk of bleeding complications should be determined in the context of the environment in which it is carried out. OBJECTIVE: To determine the complications of the patients in anticoagulant therapy, in our environment, and to analyse the of risk factors. PATIENTS AND METHODS: We have studied the complications suffered by 300 patients who underwent anticoagulation for cardiac diseases, between March-94 and March-96 retrospectively. We have classified the complications in two groups: a) Fatal or intracranial with sequelae. b) Those requiring hospitalization and/or transfusion. Univariate and multivariant analyses were conducted to identify predictors of complications, including the following factors: age, sex, diabetes, hypertension, length of therapy, distance from our Center to their place of residence, INR (> 3 vs 2 to 3) and number of drugs associated with Acenocoumarol (> or = 3 vs 2 or less). RESULTS: During the follow-up 24 patients died due to non haemorrhagic complications; 3 left the treatment on their cardiologist recommendation; 2 moved their place of residence and 1 was lost in the follow-up. Of 270 remaining 3 (0.55/100 patients-year) had complications of group a and 21 (3.88/100 patients-year) of grub b. INR > 3 and multiple medications were shown as predictors of complications when including some of the complications considered. CONCLUSIONS: 1) During two years of follow-up 1.1% (0.55/100 patients-year) of patients in anticaogulant therapy had bleeding complications resulting in death or neurological sequelae. 2) When including some of the complications considered the percentage rises to 4.44/100 patients-years. 3) Although there were no differences statistically significant, INR > 3 and polymedication have been found as predictors risk factor. 4) Patients with INR of 2 to 3 and non polymedicated presented a low risk of bleeding complications (1.66/100 patients-year).

Assessment of right ventricular function and interstitial fibrosis in idiopathic dilated cardiomyopathy: hemodynamic correlates and prognostic value.

BACKGROUND: Right ventricular (RV) function and morphometric quantitation of interstitial fibrosis in idiopathic dilated cardiomyopathy (IDC) have not been the subject of specifically designed clinical observations. In particular, their role in routine assessment and prognostic evaluation of patients (pts) with IDC remains to be settled. METHODS: Eighty-one consecutive IDC patients (63 M, 18 F; mean age 52 +/- 11 yrs) with left ventricular (LV) systolic dysfunction (angiographic ejection fraction - EF - < 55%), normal coronary arteries and no histologic evidence of myocarditis were studied. Cardiac catheterization and endomyocardial biopsy (EMB) were routinely performed in all cases. RV volumes and EF were obtained by angiography according to Ferlinz' method and interstitial fibrosis was quantitated by computer-assisted morphometric analysis. These data were analyzed in order to study correlations with hemodynamic parameters and to assess their prognostic value in a long-term follow-up. RESULTS: In the study population, right ventricular EF was significantly lower than in normal controls (35 +/- 11% vs 53 +/- 6%, p < 0.0001) and showed a significant positive correlation with LV EF (r = 0.54; p < 0.0001), and a weak but significant negative correlation with fibrosis (r = -0.29; p = 0.03). RV volumes, but not EF, were significantly related to mean pulmonary pressure. At multivariate analysis, RV end-diastolic volume (EDV) and EF were the two independent predictors of severe heart failure (NYHA class III-IV). After a mean follow-up of 64 +/- 36 months, 20 pts died and 9 had heart transplantation, for a 63% transplant-free survival rate (TFS). Multivariate analysis identified three independent predictors of TFS: LV stroke work index (p < 0.0001), RV stroke work index (p = 0.02) and RV EDV (p = 0.03). Fibrosis was predictive of survival only in the subgroup with LV EF < 20%. CONCLUSIONS: Assessment of RV function provides useful information in the evaluation of hemodynamic profile and prognosis of pts with IDC. Quantitation of interstitial fibrosis by morphometry provides little additional data.

Rescue PTCA for a totally occluded left main coronary artery in acute myocardial infarction with cardiogenic shock: technical success and long-term survival.

Percutaneous transluminal coronary angioplasty was performed after failed thrombolysis in a 54-year-old man for total occlusion of the left main coronary artery in the setting of acute myocardial infarction with cardiogenic shock. The procedure was successful in terms of vessel recanalization and restoration of flow. The recovery of muscle function was limited due to the time lag between onset of symptoms and recanalization. This case highlights the crucial role of early identification and prompt referral of patients with extensive ischemia to centers with the capability for emergency percutaneous revascularization procedures.

[Troponin T, Troponin I and CK-MB (mass) in the detection of periprocedural myocardial damage after coronary angioplasty]. / Troponina T, troponina I e CK-MB (massa) nel riconoscimento del danno miocardico periprocedurale dopo angioplastica coronarica.

The development of methods for the detection of circulating CK-MB mass, cardiac troponin T (cTn-T) and troponin I (cTn-I) has increased the diagnostic potential in the identification of myocardial damage. Coronary angioplasty (PTCA) represents a widely accepted revascularization procedure and a clinical model of induced ischemia. Using these new biochemical markers, we evaluated the incidence and the clinico-procedural correlates of minor myocardial damage (MMD) in a series of patients treated with PTCA in our Department. In 57 consecutive patients (75% males; mean age 58 years; range 35-80) undergoing elective PTCA from March 1 to June 30, 1995, serum levels of CK-MB mass, cTn-T and cTn-I were measured at baseline and at 6, 12 and 24 hours after the procedure. Seventy-eight coronary stenoses were dilated (mean 1.4 lesion/patient), 17 of these were in infarct-related vessels; 8 were total occlusions and 2 were located in saphenous vein grafts. Twenty-two procedures were completed by coronary stenting (17 elective). cTn-T and cTn-I were considered abnormal when serum levels were > 0.2 ng/ml and > 0.6 ng/ml, respectively. CK-MB mass was also determined in all patients (abnormal > 5 ng/ml). No patients had clinical or electrocardiographic evidence of myocardial infarction after the procedure. Overall, 16 patients (28%) developed biochemical evidence of post-procedural MMD (defined as the presence of at least one abnormal sample of any among the three markers tested). Four (7%) had abnormal CK-MB mass (at least one sample), 9 (16%) abnormal cTn-T, and 15 (26%) abnormal cTn-I. When CK-MB mass was elevated, both cardiac troponins were also elevated. In patients positive for MMD and abnormal CK-MB mass, peak cTn-I was significantly higher than in patients with normal CK-MB (3.02 +/- 1.07 vs 1.02 +/- 0.11 ng/ml; p = 0.009). The difference was not evident when comparing the same groups of patients for cTn-T (0.26 +/- 0.04 vs 0.18 +/- 0.10 ng/ml; p = 0.16). Also, peak cTn-I but not peak cTn-T had a positive correlation with peak CK-MB mass (r = 0.89; p < 0.0001 and r = 0.23; p = 0.40). The elevation of either marker of MMD was not related to clinical, angiographic or procedural variables. A possible interpretation for MMD was found in 2/3 of cases: bail-out (2); late occlusion (1); minor side branch occlusion (3); distal embolization from saphenous vein grafts (2) or total occlusions (2). In our series, MMD after PTCA occurs in 28% of cases and is unrelated to clinical, angiographic and procedural variables. Both cTn-T and cTn-I increase the sensitivity of CK-MB mass in the detection of MMD after PTCA, cTn-I being the most sensitive marker. In about 1/3 of cases, the presence of MMD remains unexplained. The prognostic implications of MMD are as yet undefined.

Troponin T, troponin I and creatine kinase-MB mass after elective coronary stenting.

OBJECTIVE: To assess whether and to what extent elective coronary stenting is associated with biochemical evidence of minor myocardial damage (MMD), as defined by the detection of abnormal post-procedural serum levels of one more among the following markers of ischaemic injury: creatine kinase (CK)-MB mass, troponin T (Tn-T) and troponin I (Tn-I). METHODS: Nineteen elective procedure of coronary stenting were compared with a matched group of 25 conventional percutaneous transluminal coronary angioplasty (PTCA) procedures performed in our laboratory from March to June 1995. Cases with evolving or recent (< 2 weeks) myocardial infarction, chronic total occlusions and dilation of saphenous vein grafts were excluded. By definition, all of the patients had undergone uneventful deployment of a single palmaz-Schatz stent, with no chest pain and no persistent ECG changes after the procedure. Serum levels of CK-MB mass, Tn-T and Tn-I were determined at baseline and 6, 12 and 24 h after the procedure. The frequency of abnormal results was determined for each marker. Baseline and peak post-procedural levels in the two groups were compared and related to procedural variables. RESULTS: Baseline values were normal in all cases. The quantitative analysis showed that post-procedural levels of each marker (including total CK) were significantly higher with respect to baseline in both groups. In the stent group, two patients had positive CK-MB mass, four positive Tn-T and seven positive Tn-I. Absolute changes in Tn-T and Tn-I were closely related to changes in CK-MB mass (r = 0.76, P < 0.0001; r = 0.90, P < 0.0001), respectively). Three of these patients developed clinically silent side-branch occlusion. All of them were positive for troponins and two were positive for CK-MB. No correlation was found between procedural variables and the results of biochemical assays. In the PTCA group, three patients were positive for Tn-I, whereas the CK-MB mass and Tn-T remained constantly normal. No side-branch occlusion was observed. The peak CK-MB mass and Tn-I were significantly higher in the stent group than they were in the PTCA group (3.04 +/- 4.1 versus 1.27 +/- 1.3 ng/ml, P = 0.046; 0.78 +/- 1.17 versus 0.28 +/- 0.3 ng/ml, P = 0.046, respectively). This difference was no longer apparent when patients with side-branch occlusion were excluded. CONCLUSIONS: In our series, Tn-I measurement shows the highest ability to detect MMD, being positive in 37% of stent and 14% of PTCA cases. Elective coronary stenting associated with greater release of CK-MB mass and Tn-I than is conventional PTCA. This finding is mainly determined by cases of side branch occlusion, which account for most, but not all, periprocedural MMD in the stent group.

A multicenter study on the hospitalization of pediatric patients on chronic peritoneal dialysis.

The Italian Registry of Pediatric Chronic Peritoneal Dialysis (CPD) carried out a special study on patient hospitalization during the years 1989-1992. Ninety-two children (mean age 8.4 +/- 4.7 years) entered the study, for a total of 1406 CPD-months. The contribution of the different causes of hospitalization for a total of 4683 hospital days was: CPD training 31%; routine controls 14%; CPD-related complications 35%; clinical complications 14%; other causes 6%. The rate of patient hospitalization that resulted was 3.33 days/CPD-month; it was higher in the first year (4.32 days/CPD-month) than in the second year (1.64 days/CPD-month) or in the third year (2.25 days/CPD-month). This difference was mainly due to the need for the training at the start of the CPD treatment. The evaluation of the hospitalization rate in different age groups showed a statistically significant difference (p < 0.05) between the group 0-2 years (5.47 days/CPD-month) and the group 3-15 years (2.78 days/CPD-month). Complications were the cause of 150 admissions to the hospital (1:9.6 CPD-months). Ninety-eight admissions were due to CPD-related complications: peritonitis (33%), problems with the catheter (19%), abdominal hernias (4%), and others (9%). Among clinical complications (52 admissions), the main cause of hospitalization was hypertension (15%), followed by infections (4%), and malnutrition (3%).

Chronic peritoneal dialysis catheters in pediatric patients: experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis.

During the period 1986-1991, 140 pediatric patients [age < or = 15 years at the start of chronic peritoneal dialysis (CPD)], belonging to 15 dialysis centers, were enrolled in the Italian Registry of Pediatric Chronic Peritoneal Dialysis. Data on 188 peritoneal catheters were collected: 161 catheters were Tenckhoff (144 double-cuff, 17 single-cuff), and 27 were two-cuff Valli-type catheters. All catheters were surgically inserted; the entry site was in the midline in 84 cases and paramedian in 104. An omentectomy was performed in 78.8% of the cases. Apart from peritonitis, there were 161 catheter-related complications (103 exit-site infections, 17 leakages, 15 obstructions, 15 outer-cuff extrusions, 5 hemoperitoneum, 6 others) observed during 2687.5 dialysis-months, with an incidence of one complication every 16.7 dialysis-months. Fifty-five catheters (29.2%) were removed; infection (39 cases) was the main cause for removal, followed by obstruction (9 cases), dislocation, and outer-cuff extrusion (2 cases each). Actuarial survival of all catheters was 79.7% at 1 year, 66.6% at 2 years, 42.8% at 3 years, and 39.8% at 4 years. No difference in catheter survival was observed according to the entry site. When considering the age of the patients at catheter insertion, a difference close to statistical significance was found (p = 0.06).

Atresia of the left main coronary artery: clinical recognition and surgical treatment.

Atresia of the left main coronary artery is an extremely rare anomaly with very few cases presented in the literature. Even more uncommon are reports of successful surgical repair. This article concerns two cases of atresia of the left main coronary artery treated surgically with a favourable outcome. The two patients (a 16 year-old boy and a 43 year-old woman) had a different clinical presentation but identical angiographic and morphologic features. The authors examine the embryogenetic defect underlying this anomaly. The differential diagnosis involves two congenital malformations (single coronary artery and anomalous origin of the left coronary artery from the pulmonary trunk) and acquired atherosclerotic disease of the left main coronary artery; the distinguishing features of these conditions are reviewed. Surgical management by means of internal mammary artery revascularization is discussed in light of recent reports about adequacy of blood flow in internal mammary artery bypass grafts.

Chronic peritoneal dialysis in paediatrics: experience of a national registry.

The results of the first 3 years' collaboration of the Italian Registry of Paediatric Chronic Peritoneal Dialysis (CPD) (1986-1988) are presented. This Registry acquired data on the majority of the paediatric patients treated with CPD in Italy, thus providing a national picture in a field where few nationwide surveys are available. Patients of less than 15 years of age at the start of dialysis were enrolled and clinical data collected until the age of 19 years. The number of nephrological paediatric centres participating in the Registry increased from 7 in 1986 to 11 in 1988. The total number of patients on CPD was 70 and the percentage of dialysed children treated with CPD ranged from 40.2% to 43.6%. Data on 89 peritoneal catheters were collected: during 1417 dialysis-months 70 catheter-related complications were observed (1:20.8 dialysis-months); actuarial catheter survival was 92.7% at 6 months, 84.8% at 1 year and 68.8% at 2 years. the incidence of peritonitis changed from 1 episode every 10.9 patient-months in 1986 to 1 every 19.8 in 1988. Abdominal hernias were the other main clinical complication observed. The survival of patients was 92.5% at 3 years, while the technique survival at the same time was 84%.

Five years' experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis.

The results of the first 5 years' experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis (CPD) (1986-1990) are presented. Patients of less than 15 years of age at start of dialysis were enrolled and clinical data collected until the age of 19. The number of the dialysis centres participating in the Registry increased from 7 in 1986 to 15 in 1990. The total number of patients on CPD was 119, the number of new patients per year ranged from 15 to 28 and the percentage of all dialysed children treated with CPD increased from 40% in 1986 to 49% in 1990. The age of patients at start of CPD was 8.5 +/- 4.9 years and 16% of them were under 2 years. Only CAPD was utilized in 1986, while CCPD/NPD accounted for 53% and 65% of the treated patients in 1989 and 1990, respectively. At 4 years, patient survival was 91.3% and technique survival 79.3%. A comparison between data of 48 patients on CPD and 34 on hemodialysis, who started dialysis in the period 1989-1990, showed that CPD was the most frequent form of initial therapy (56%) and was the treatment of choice for children younger than 4 years.

Effect of hemodialysis and hemodiafiltration on uremic neuropathy.

This study was undertaken to compare the effect of 1 year hemodialysis (HD) or hemodiafiltration (HDF) treatment on peripheral neuropathy. Thus 21 of 42 patients on chronic HD (1-1.3 m2 cuprophane dialyzer, Qb 300 ml/min) were switched to HDF (1.3 m2 polysulfone dialyzer, Qb 400 ml/min, substitution volume 9-13 liters, ultrafiltration rate 60-70 ml/min), while the remaining patients were considered as a control group. Treatment time was scheduled both in HD and HDF to maintain adequate BUN levels in relation to protein catabolic rate. However, HDF provided a significantly greater weekly inulin (MW 5,000) clearance than HD (5.8 +/- 1.2 vs. 1.6 +/- 0.2 ml/min; p less than 0.001). HD and HDF groups were comparable for age, time on dialysis and starting electroneurographic parameters, which were on average within the normal range. After 1 year follow-up, creatinine, hematocrit, calcium, phosphate, PTH, BUN, protein catabolic rate and residual GFR were comparable in the two groups, whereas beta 2-microglobulin was significantly reduced in HDF patients (29 +/- 6.7 vs. 38.8 +/- 13.9 mg/l in HD patients, p less than 0.01). During the 1-year treatment, electroneurographic parameters did not change in HDF patients, whereas a significant decrease of ulnar motor nerve conduction velocity, ulnar muscle action potential amplitudes, median sensory nerve conduction velocity and peroneal muscle action potential amplitudes was detected in HD patients. We conclude that HDF might prevent the worsening of the electroneurographic indices occurring during chronic HD treatment, as it provides a more effective removal of middle and larger molecules than HD. The use of a more biocompatible membrane in HDF might further contribute to this favorable effect on uremic neuropathy.

Acute coronary occlusion after recent coronary angioplasty. Association with exercise and successful treatment with intracoronary thrombolysis.

A case of coronary occlusion occurred seven days after successful percutaneous transluminal coronary angioplasty. The acute complication occurred shortly after a negative exercise stress test and was resolved with intracoronary urokinase.

Improved biocompatibility by modified cellulosic membranes: the case of hemophan.

The rising problem of biocompatibility is encouraging the development of new dialysis membranes, but the high cost of synthetic ones precludes their wide use. The authors compared the biocompatibility of cuprophan (CU), cellulose acetate (CA), and hemophan (HE), evaluating both in vitro and in vivo polymorphonuclear leukocyte (PMN) oxidative metabolism activation by resting chemiluminescence and complement activation by C3a; in vivo PMN counts during dialysis were also performed. The lowest increase in in vitro PMN resting chemiluminescence using HE was + 71.3% with CA, +49.3% with CU, and + 21.4% with HE (p less than 0.001 versus CA and CU); furthermore, HE did not significantly stimulate PMN resting chemiluminescence during in vivo hemodialysis: + 56.6% with CA, + 38.8% with CU, and + 3.7% with HE (p less than 0.01 versus CU and p less than 0.001 versus CA). C3a concentration increased with all membranes both in vitro and in vivo, but HE (in both experimental conditions) showed the lowest increase at any time (p less than 0.001 versus CA and CU). After 15 min of dialysis, PMN count dropped to 20.3% of basal values with CU, to 49.8% with CA, and to 76.5% with HE (p less than 0.001 versus CU and CA). Among cellulosic membranes, HE is the most biocompatible and appears to be an important step in preventing blood-membrane interactions and related complications.