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At least 73 records · Page 4Linked to original sources

PubMed1998

Functional hemodynamic assessment of the 21-mm and 23-mm CarboMedics Top Hat aortic prosthetic valve.

Between 1993 and 1996 the CarboMedics Top Hat supraannular aortic valve was implanted in 41 patients at the Wessex Cardiothoracic Centre (age, 39 to 74 years; mean, 61.3+/-8.9 years). Comparisons of annular dimensions made at surgery indicate that conventional annular valve replacement would have required at least a size smaller valve. This was particularly marked when a prosthetic mitral valve was in place. Operative mortality was 2.4%. There were also three late deaths. Echocardiography before and after symptom-limited treadmill testing has been performed in 21 patients. The mean time to follow-up was 16.1 months. The Doppler-derived indices of forward flow pre- and postexercise were expressed as mean+/-standard deviation. For 23-mm valves the values were: peak valve gradient 21.43+/-7.46 mm Hg and 35.86+/-14.4 mm Hg, aortic valve area 1.13+/-0.39 cm2 and 1.24+/-0.54 cm2. For 21-mm valves the values were: peak valve gradient 24.84+/-8.2 mm Hg and 31.29+/-5.84 mm Hg, aortic valve area 1.08+/-0.44 cm2 and 0.95 +/-0.2 cm2. The Top Hat valve has a good hemodynamic profile at rest and during exercise. Surgical considerations make it particularly useful in patients with a small aortic annulus and in patients undergoing combined aortic and mitral valve replacement.

Adult↗

PubMed1990

Balloon dilatation of the mitral valve by a single bifoil (2 x 19 mm) or trefoil (3 x 15 mm) catheter.

The efficacy of balloon dilatation of the mitral valve by a bifoil (2 x 19 mm) or trefoil (3 x 15 mm) catheter (single catheter technique) was assessed in 53 patients (mean age 28) with mitral stenosis, most of whom were women. The procedure was unsuccessful in three patients. After balloon dilatation the left atrial pressure decreased from 22 mm Hg to 13 mm Hg and the mitral valve gradient from 12 mm Hg to 4 mm Hg. The mitral valve area increased from 0.7 cm2 to 2.1 cm2. Exercise time on the standard Bruce protocol increased from 3.9 minutes to 7.2 minutes. In 22 (44%) patients mitral regurgitation developed or the grade of regurgitation increased. Left to right shunts with pulmonary to systemic flow ratios greater than 1:5 were detected in four patients. Transient cerebrovascular episodes developed in two patients. One patient died after emergency valve replacement for severe mitral regurgitation. Balloon dilatation of the mitral valve by the single catheter technique with the bifoil or trefoil catheters is an effective treatment for patients with mitral stenosis. Mild mitral regurgitation is a frequent complication of the procedure.

Adolescent↗

PubMed1998

Primary Stenting for Coronary Artery Lesions 15Ð18 mm in Length: A Preliminary Experience with the Long (18 mm) Palmaz-Schatz Stent.

BACKGROUND: Currently little data exists on the use of single intracoronary stents for the treatment of long coronary artery lesions. The aim of this study was to evaluate the 18 mm Palmaz-Schatz stent (PS no. 204C) for the primary treatment of native coronary lesions between 15 mm and 18 mm in length. METHODS: A consecutive group of 17 patients were included in this study over a 3 month period. Each patient selected was felt suitable for elective treatment with an intracoronary stent and had a coronary artery lesion of >15 mm in length. Coronary arteriograms recorded just before PTCA, after full stent deployment and electively at 4 months after stent deployment were analyzed using semi-quantitative coronary angiography. RESULTS: Mean lesion length treated was 16.9 mm. The primary success rate for stent delivery was 16 out of 17 lesions. One patient required immediate coronary artery bypass surgery for extensive dissection of the right coronary artery. There were no out of hospital complications and no patient suffered acute or subacute stent thrombosis. All patients had an improvement in their Canadian Cardiovascular Angina Class: Three patients (21%) had asymptomatic restenosis (stenosis 50%) at follow-up angiography. CONCLUSION: This study shows the 18mm Palmaz-Schatz stent is relatively successful for the elective treatment of long coronary artery stenoses. Although the mean lesion length of 16.9 mm in this study is significantly greater than that of the BENESTENT and STRESS studies, the 21% restenosis rate is comparable.

Journal Article↗

PubMed1995

[Acute myocardial infarction without elevation of CK activity: analysis of CK-MM protein and gene of CK-MM].

A 56 year old female patient had acute myocardial infarction which was confirmed by autopsy. However the patient showed no elevation of CK activity in the serum. We proved the deficiency of CK-MM protein in her serum as well as in the myocardial tissues. To further elucidate the molecular mechanism we isolated and characterized genomic DNA and cDNA of CK-MM from the myocardial tissue of the patient and demonstrated the depression of mRNA of CK-MM which might be related with the deficiency of CK-MM protein. Point mutation at codon 54 [Exon 2, GAC (Asp)-->GGC(Gly)] was also demonstrated on the beta-sheet of CK-MM. Association of point mutation with depressed CK-MM is to be clarified.

Base Sequence↗

PubMed2000

Acute and late outcome after use of 2.5-mm intracoronary stents in small (< 2.5 mm) coronary arteries.

We describe the high-pressure deployment of 2.5-mm stents in small (< 2.5 mm) coronary vessels. Forty-three lesions in 40 patients were treated. The mean reference vessel diameter was 2.3 +/- 0.2 mm. The mean % luminal stenosis was 90 +/- 9. The mean lesion length was 11. 7 +/- 9.1 mm. Sixteen lesions were pretreated with rotational atherectomy, and the remainder with PTCA. The rate of successful stent deployment was 41/43 (95%). The mean postintervention % stenosis was -1 +/- 10. There were no in-hospital deaths or procedure-related Q-wave MI. The patients were followed for a mean of 18 months. Eight patients (or 21%) developed recurrent chest pain and/or angiographically proven restenosis. One patient (3%) developed intermediate restenosis. Twenty-nine patients (or 76%) either remain symptom-free or have patent target sites on repeat angiography. It appears that reasonable acute and long-term results can be achieved with 2.5-mm stents in small coronary arteries using high-pressure deployment techniques. Cathet. Cardiovasc. Intervent. 49:121-126, 2000.

Adult↗

PubMed2002

Clinical outcome in patients with 19-mm and 21-mm St. Jude aortic prostheses: comparison at long-term follow-up.

BACKGROUND: Small-sized prostheses for aortic valve replacement may result in residual left ventricular outflow tract obstruction. Aim of the study was to verify whether implantation of 19-mm versus 21-mm St. Jude Medical standard prostheses (St. Jude Medical, Inc, St. Paul, MN) influences long-term clinical outcome. METHODS: Two hundred twenty-nine patients who underwent aortic valve replacement with 19 mm (group 1, 53 patients) or 21-mm St. Jude Medical standard prostheses (group 2, 176 patients) were included in the study. Mean follow-up of current survivors was 10+/-4 years. RESULTS: Operative mortality was 7.5% in group 1 and 8.5% in group 2. At discharge, an important patient-prosthesis mismatch (effective orifice area index < or = 0.60 cm2/m2) was present in 18% of group 1 versus 5% in group 2 (p = 0.004). Among patients with body surface area less than 1.70 m2, such mismatch was present in 15% of group 1 versus 2% of group 2 (p = 0.008). At last follow-up New York Heart Association (NYHA) functional class (p < 0.001), left ventricular mass reduction (p = 0.02), mean (p = 0.002) and peak transprosthetic gradients (p < 0.001), and effective orifice area index (p = 0.005) were significantly better in group 2. Freedom from sudden death (92%+/-5% vs 99%+/-1%, p = 0.01), valve-related death (84%+/-6% vs 90%+/-5%, p = 0.02), and cardiac events (56%+/-13% vs 86%+/-4%, p = 0.008), were significantly lower in group 1. Effective orifice area index was an independent predictor of late cardiac events. CONCLUSIONS: Although long-term results after aortic valve replacement with small-sized St. Jude Medical standard prostheses are satisfactory, 19-mm valve recipients show a high prevalence of important patient-prosthesis mismatch with less evident functional improvement and higher rate of cardiac events, suggesting a very cautious use of this prosthesis.

Aged↗

PubMed1997

Corneal changes after cataract surgery with 5.0 mm sutured and 3.5 mm sutureless clear corneal incisions.

PURPOSE: To study corneal changes after endocapsular phacoemulsification cataract extraction and intraocular lens (IOL) implantation with a 3.5 mm clear corneal sutureless incision or a 5.0 mm clear corneal incision with an absorbable suture. SETTING: Northwest Kansas Eye Clinic, Hays, Kansas, USA. METHODS: In a prospective study, 200 eyes were randomly distributed into two groups. Group A comprised 100 eyes that had a silicone IOL inserted through a 3.5 mm sutureless clear corneal incision. Group B comprised 100 eyes that had a 5.0 mm poly(methyl methacrylate) (PMMA) IOL inserted through a 5.0 mm clear corneal incision; one half of the closures used a single radial suture (Group B1), and the other half, an X suture (Group B2). Preoperatively, corneal topography and corneal endothelial cell counts were performed. Six to 8 months postoperatively, they were repeated and evaluated. Differential topography was used to determine the difference between the preoperative and postoperative corneas. During the final postoperative visit, IOL centration was evaluated. RESULTS: All closures produced only minimal changes in the corneal topographic indices. The postoperative corneas closely resembled the preoperative corneas. Polar K values showed a slight astigmatic shift in all groups. Group B2 was the only one to exhibit a with-the-rule shift. The change in endothelial cell counts was minimal and comparable in all three groups. CONCLUSION: The small amount of change in the corneal indices, especially in surface regularity, indicates that all corneas were relatively comparable and stable 6 to 9 months postoperatively regardless of the type of incision and closure method.

Adult↗

PubMed1999

Corneal astigmatism after cataract surgery with 4.1 mm BENT scleral and 4.1 mm plus meridian corneal incisions.

PURPOSE: To determine whether the 4.1 mm BENT (between 9 and 12 o'clock) scleral incision or the 4.1 mm plus meridian corneal incision (PMCI) is better at minimizing postoperative astigmatism. SETTING: Department of Ophthalmology, Kobe City General Hospital, Kobe, Japan. METHODS: This prospective study comprised 58 eyes of 29 consecutive patients with bilateral cataract. One eye was randomly assigned to have cataract surgery with a 4.1 mm BENT scleral incision and the other eye, with a 4.1 mm PMCI. Corneal astigmatism was measured before surgery and 1, 3, 10, 30, and 100 days after surgery. RESULTS: Mean astigmatism preoperatively and on postoperative days 1, 3, 10, 30, and 100 in the BENT scleral incision group was 0.99 +/- 0.66, 1.53 +/- 1.11, 1.12 +/- 0.72, 1.26 +/- 0.81, 1.16 +/- 0.73, and 1.09 +/- 0.64 diopters (D), respectively. Means in the PMCI group were 1.14 +/- 0.79, 1.38 +/- 0.98, 1.17 +/- 0.88, 1.31 +/- 0.77, 1.01 +/- 0.70, and 1.00 +/- 0.60 D. respectively. Astigmatism on days 1 and 10 postoperatively was significantly greater than preoperatively in the BENT group (P < .03) but not in the PMCI group. The changes in astigmatism were less in the PMCI group at every examination and were significantly different 30 days postoperatively (P < .05). The negative correlation between preoperative astigmatism and the final postoperative change was significant in both groups (P < .032); the value of x-intercept of the regression line was 1.37 D in the BENT scleral incision group and 0.82 D in the PMCI group. CONCLUSION: In cataract surgery using a 4.1 mm incision, the PMCI surpassed the BENT scleral incision in minimizing postoperative corneal astigmatism.

Adult↗

PubMed2001

Use of MM-PBSA in reproducing the binding free energies to HIV-1 RT of TIBO derivatives and predicting the binding mode to HIV-1 RT of efavirenz by docking and MM-PBSA.

In this work, a new ansatz is presented that combines molecular dynamics simulations with MM-PBSA (Molecular Mechanics Poisson-Boltzmann/surface area) to rank the binding affinities of 12 TIBO-like HIV-1 RT inhibitors. Encouraging results have been obtained not only for the relative binding free energies, but also for the absolute ones, which have a root-mean-square deviation of 1.0 kcal/mol (the maximum error is 1.89 kcal/mol). Since the root-mean-square error is rather small, this approach can be reliably applied in ranking the ligands from the databases for this important target. Encouraged by the results, we decided to apply MM-PBSA combined with molecular docking to determine the binding mode of efavirenz SUSTIVA(TM) another promising HIV-1 RT inhibitor for which no ligand-protein crystal structure had been published at the time of this work. To proceed, we define the following ansatz: Five hundred picosecond molecular dynamics simulations were first performed for the five binding modes suggested by DOCK 4.0, and then MM-PBSA was carried out for the collected snapshots. MM-PBSA successfully identified the correct binding mode, which has a binding free energy about 7 kcal/mol more favorable than the second best mode. Moreover, the calculated binding free energy (-13.2 kcal/mol) is in reasonable agreement with experiment (-11.6 kcal/mol). In addition, this procedure was also quite successful in modeling the complex and the structure of the last snapshot was quite close to that of the measured 2,3 A resolution crystal (structure the root-mean-square deviation of the 54 C(alpha) around the binding site and the inhibitor is 1.1 A). We want to point out that this result was achieved without prior knowledge of the structure of the efavirenz/RT complex. Therefore, molecular docking combined with MD simulations followed by MM-PBSA analysis is an attractive approach for modeling protein complexes a priori.

Alkynes↗

PubMed2000

Should the definition of preeclampsia include a rise in diastolic blood pressure of >/=15 mm Hg to a level <90 mm Hg in association with proteinuria?

OBJECTIVE: This study was undertaken to compare baseline characteristics and pregnancy outcomes between normotensive women who did and those who did not have a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria. STUDY DESIGN: We studied 4302 healthy nulliparous women from the Calcium for Preeclampsia Prevention trial who were delivered at >/=20 weeks' gestation. We selected as the study group normotensive women who developed proteinuria within 7 days of a rise in diastolic blood pressure of >/=15 mm Hg with respect to baseline on 2 occasions 4 to 168 hours apart. Baseline blood pressure was the mean of measurements at 2 clinic visits before 22 weeks' gestation. Other normotensive women used for comparison were those who did not develop gestational hypertension or a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria. RESULTS: Except for greater weight (P <.001), body mass index (P <.001), and systolic blood pressure (P =.05) the baseline characteristics of the 82 women with a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria did not differ significantly from those of the other normotensive women. Although they had a greater rate of weight gain (P <.005), larger babies (P =.06), and a 2-fold increase in abdominal delivery (P <.001), there was little other evidence of adverse pregnancy outcomes among these women. CONCLUSION: During normotensive pregnancy a rise in diastolic blood pressure of >/=15 mm Hg in association with proteinuria appears to be benign and is not a useful clinical construct.

Birth Weight↗

PubMed1990

Post-dural puncture headache in young patients. A comparative study between the use of 0.52 mm (25-gauge) and 0.33 mm (29-gauge) spinal needles.

In a prospective study of 80 patients under 40 years of age, given spinal anaesthesia through either a 0.52 mm (25-gauge) needle or a 0.33 mm (29-gauge) needle, the incidence of post-dural puncture headache and backache was compared. There were no headaches in the 0.33 mm needle group, while in the 0.52 mm needle group an incidence of 25% was found. The incidence of backache was the same in both groups. The technique of performing spinal anaesthesia was evaluated and concluded to be slightly more difficult with a 0.33 mm needle, as estimated by the number of redirections of the needle needed to obtain cerebrospinal fluid. There were no differences between the two needles with respect to obtaining adequate spinal anaesthesia and spread of blockade.

Adult↗

PubMed2002

Co-immunization with M-CSFR and mM-CSF DNA vaccines is better than M-CSFR-mM-CSF fusion DNA vaccine.

BACKGROUND AND OBJECTIVES: DNA vaccine against macrophage colony-stimulating factor receptor (M-CSFR) has shown both protective and therapeutic effects. In this study, we explore the possibility of using DNA vaccines against both M-CSFR and membrane-bound macrophage colony-stimulating factor (mM-CSF) to achieve better effects. DESIGN AND METHODS: Three plasmids were constructed by inserting either extracellular and transmembrane region of mM-CSF (pM), or extracellular region of M-CSFR (pR), or extracellular region of M-CSFR linked with extracellular and transmembrane regions of mM-CSF by a (Gly Gly Ser)2 flexible linker (pF), into pcDNA3.1. A SP2/0 cell line stably expressing pF (SP2/0-F) was established to evaluate humoral and cytotoxic immune responses as well as therapeutic and preventive effects induced by pM, pR, pF or pM+pR vaccination in BALB/c mice. The mechanisms of these vaccinations were also studied by monitoring the release of interleukin (IL)-4 and interferon (IFN)-g by splenocytes upon activation. RESULTS: Vaccination against two epitopes had better effects than against a single epitope while vaccination by pM+pR had the greatest effects on inducing humoral and cytotoxic immune responses, prolonging survival of mice challenged with SP2/0-F, and inducing IL-4 and IFN-g release by splenocytes. INTERPRETATION AND CONCLUSIONS: Our results suggest that co-immunization of M-CSFR and mM-CSF DNA vaccines is better than M-CSFR-mM-CSF fusion DNA vaccine.

Animals↗

PubMed1994

[Induced astigmatism in cataract surgery. Scleral tunneling incisions of 5.5 mm and 6.5 mm after 1-year follow-up].

To evaluate the effect of scleral pocket incisions closed with a single horizontal suture on postoperative astigmatism, 97 patients were enrolled in a prospective study. After 1 year of follow-up the data of 80 patients could be analysed. Routine phacoemulsification was performed in all patients consecutively by one surgeon. 40 patients received a posterior chamber lens with a 5 mm by 6 mm oval polymethylmethacrylate (PMMA) optic (group I), and 40 patients received an intraocular lens with a 6 mm diameter round PMMA optic (group II). The incisions were 5.5 mm and 6.5 mm, respectively. Follow-up visits including keratometry were scheduled 1 day, 5 days, 3 months, 6 months and 1 year postoperatively. The induced astigmatism was calculated using vector analysis. One day after operation the mean induced cylinder was 1.22 D in group I and 1.06 D in group II. After 5 days it amounted to 1.09 D (group I) and 1.03 D (group II), and at 3 months it was 1.07 D and 1.00 D, respectively. Six months after operation the induced cylinder was 1.04 D (group I) and 0.96 D (group II), and at 1 year it was 1.02 D and 0.81 D. There was no statistically significant difference between the groups at any time (Wilcoxon test, P > 0.05). We conclude that scleral pocket incisions closed with a single horizontal suture induce about 1 D of corneal astigmatism, with stability over time. There is no clinical advantage in reducing the incision width by using oval optics.

Aged↗

PubMed2005

Comparison between a 7 French 6 mm tip cryothermal catheter and a 9 French 8 mm tip cryothermal catheter for cryoablation treatment of common atrial flutter.

BACKGROUND: Larger tipped cryothermal catheters may deliver efficacy and procedure benefits in the treatment of patients with atrial flutter. OBJECTIVE: To compare 7 French 6 mm and 9 French 8 mm tip cryothermal catheters (Freezor, Xtra or Freezor, MAX, CryoCath Technologies Inc., Kirkland, Canada) in terms of acute and chronic efficacy, and procedure characteristics in the treatment of atrial flutter. METHODS: This non-randomized clinical investigation determined bi-directional isthmus block at intervention, procedure characteristics, and symptom and conduction recurrence rates post procedure in consecutive patients with symptomatic atrial flutter ablated either with the 7 French 6 mm tip cryothermal catheter (n = 43) at -75 degrees C for 4 minutes or the 9 French 8 mm tip cryothermal catheter (n = 51) at -75 degrees C for 8 minutes. RESULTS: Clinical data showed a higher acute success rate for the larger tipped catheter (100% vs. 88%). Symptom recurrence rates were 0% for both catheters at 3, 6, and 9 month follow-up. Conduction recurrence rates were similar for both catheters on repeat electrophysiological study at 3 months post procedure (35% vs. 32%). Procedure benefits were fewer cryotests (20 +/- 17 vs. 26 +/- 21) and ablations (4 +/- 4 vs. 12 +/- 18), and shorter procedure (80 +/- 61 min vs. 87 +/- 48 min), fluoroscopy (14 +/- 9 min vs. 24 +/- 10 min), and cryoapplication times (37 +/- 18 min vs. 44 +/- 23 min) with the larger tipped catheter. There were no adverse events reported. CONCLUSIONS: Clinical results showed differences in catheter performance that favoured the larger tipped catheter. However, increased acute success rate did not translate into reduced conduction recurrence rate post ablation, although clinical recurrence was completely absent long-term.

Adult↗

PubMed2004

A multicenter, open-label, randomized, two-period crossover trial comparing glycemic control, satisfaction, and preference achieved with a 31 gauge x 6 mm needle versus a 29 gauge x 12.7 mm needle in obese patients with diabetes mellitus.

BACKGROUND: Optimal needle length for subcutaneous insulin injection may differ for obese and nonobese patients, which could affect management of diabetes mellitus (DM). OBJECTIVE: The aim of this study was to determine whether 31 gauge (G) x 6 mm (shorter) needles are appropriate alternatives to 29 G x 12.7 mm (longer) needles in obese patients with DM. METHODS: A multicenter, open-label, randomized, 2-period crossover trial was conducted in insulin-treated patients with type 1 or 2 DM with body mass index >or=30 kg/m(2) and glycosylated hemoglobin A(1c) (HbA(1c)) concentration <or=10%. All patients used the same injection device and were randomized to receive 12 weeks of therapy with 1 injection site (thigh or abdomen) and 1 of the 2 needle lengths. Patients used the same injection site but the alternate needle during the second 12-week period. RESULTS: Sixty-two patients (31 men, 31 women; mean [SD] age, 50.5 [10.6] years; age range, 20-73 years) received treatment. Fifty-six patients completed all 24 weeks of treatment. No differences in glycemic control were found. Double-blind assessments of pain scores and leakage measurements, and results from the World Health Organization Diabetes Treatment Satisfaction Questionnaire and most sections of the Insulin Treatment Satisfaction Questionnaire (ITSQ), indicated no differences. However, patients indicated greater satisfaction with the shorter needle on the ITSQ (P < 0.001). The most common adverse event was injection-site bruising (51% [30/59] for the longer needle vs 34% [21/61] for the shorter needle; P = NS). Eighty-nine percent of patients (49/55) preferred the shorter needle (P < 0.001), and 76% (42/55) had a strong, very strong, or extremely strong preference for it. CONCLUSIONS: In obese patients, use of 31 G x 6 mm and 29 G x 12.7 mm needles produced comparable HbA(1c) values, double-blind pain and leakage scores, convenience, and ease of use. However, patients preferred the shorter needle.

Adult↗

PubMed2003

6.5 mm optic AcrySof implantation through a 3.0 mm incision.

An Alcon AcrySof MA50BM intraocular lens (IOL) with an optic diameter of 6.5 mm can be implanted without further enlarging a 3.0 mm phacoemulsification incision. The IOL is placed in a Monarch II B cartridge (Alcon) designed for use with the 5.5 mm optic AcrySof SA30AL, and the tip of the cartridge is inserted in the incision but not the anterior chamber. With the cartridge tip pressing against the eye, holding up the inner edge of the corneal incision and pressing down on the outer edge of it, the plunger is advanced to insert the IOL. When the entire optic has been inserted in the eye, the cartridge is withdrawn and the trailing loop is tucked in the capsular bag. We have used this procedure to perform uneventful IOL implantation in 228 consecutive eyes, after which the incisions were 3.0 to 3.1 mm in width.

Acrylic Resins↗

PubMed2000

Comparison of results of an 8-mm split-tip versus a 4-mm tip ablation catheter to perform radiofrequency ablation of type I atrial flutter.

Thirty consecutive patients with type I atrial flutter were randomized to undergo radiofrequency ablation using an 8-mm split-tip versus a 4-mm tip catheter. Procedural success was high in both groups (100% vs 93%). However, requirement of a fewer number of radiofrequency pulses and fluoroscopy time suggests superiority of the 8-mm split-tip over the 4-mm tip ablation catheter.

Atrial Flutter↗

PubMed1995

Analysis of nutrient hepatic blood flow after 8-mm versus 16-mm portacaval H-grafts in a prospective randomized trial.

BACKGROUND: In previous unrandomized studies, we demonstrated that patients undergoing 8-mm diameter portacaval H-grafts with collateral ablation (partial shunts) have lower rates of portasystemic encephalopathy (PSE) postoperatively than patients undergoing total portacaval shunts. We postulated that nutrient hepatic blood flow was greater after partial shunts because 8-mm grafts preserved some portal flow. METHODS: To test this hypothesis, we analyzed hepatic hemodynamics in 18 of 30 randomized patients who consented to be studied after complete operative recovery, grouped according to shunt size. We measured nutrient hepatic blood flow using 99m-Tc-Mebrofenin tracer elimination kinetics, and fractionated it into its portal venous and hepatic arterial components. PSE was assessed by blinded observers. Stepwise logistic regression was used to select the variable that best predicted encephalopathy. From 1989 to 1993, we conducted a randomized, prospective trial of partial (8 mm) versus total (16 mm) portacaval H-grafts. Group differences were compared using one-way analysis of variance (ANOVA). RESULTS: Hepatic encephalopathy occurred in 2 of 10 patients with partial shunts versus 5 of 8 patients with total shunts. Nutrient hepatic blood flow was significantly higher for partial shunts compared with total shunts (403 +/- 601 versus 243 +/- 17mL/min). Three variables--nutrient hepatic blood flow, portal blood flow, and hepatic arterial flow--were analyzed by stepwise logistic regression. Nutrient hepatic blood flow was selected as the best predictor of hepatic encephalopathy. In this series, PSE did not occur in any patient with more than 325 mL/min of nutrient hepatic blood flow. CONCLUSION: These findings provide a physiologic basis for clinical observations demonstrating a lower incidence of PSE with partial shunts and indicates the superiority of partial over total shunts. Partial shunts, by preserving portal flow, maintain higher nutrient hepatic blood flow than total shunts and thus minimize PSE rates.

Aniline Compounds↗