Moderate weight reduction in an outpatient obesity intervention program significantly reduces insulin resistance and risk factors for cardiovascular disease in severely obese adolescents.

Background. Metabolic risk factors like insulin resistance and dyslipidemia are frequently observed in severly obese children. We investigated the hypothesis that moderate weight reduction by a low-threshold intervention is already able to reduce insulin resistance and cardiovascular risk factors in severely obese children. Methods. A group of 58 severely obese children and adolescents between 8 and 17 years participating in a six-month-long outpatient program was studied before and after treatment. The program included behavioral treatment, dietary education and specific physical training. Metabolic parameters were measured in the fasting state, insulin resistance was evaluated in an oral glucose tolerance test. Results. Mean standard deviation score of the body mass index (SDS-BMI) in the study group dropped significantly from +2.5 ± 0.5 to 2.3 ± 0.6 (P < 0.0001) after participation in the program. A significant decrease was observed in HOMA (6.3 ± 4.2 versus 4.9 ± 2.4, P < 0.03, and in peak insulin levels (232.7 ± 132.4 versus 179.2 ± 73.3 µU/mL, P < 0.006). Significant reductions were also observed in mean levels of hemoglobin A(1c), total cholesterol and LDL cholesterol. Conclusions. These data demonstrate that already moderate weight reduction is able to decrease insulin resistance and dyslipidemia in severely obese children and adolescents.

Acute hemodynamic changes after rapid intravenous bolus dosing of dexmedetomidine in pediatric heart transplant patients undergoing routine cardiac catheterization.

BACKGROUND: Dexmedetomidine is a highly selective α(2)-adrenoceptor agonist with sedative, anxiolytic, and analgesic properties that has minimal effects on respiratory drive. Its sedative and hypotensive effects are mediated via central α(2A) and imidazoline type 1 receptors while activation of peripheral α(2B)-adrenoceptors result in an increase in arterial blood pressure and systemic vascular resistance. In this randomized, prospective, clinical study, we attempted to quantify the short-term hemodynamic effects resulting from a rapid i.v. bolus administration of dexmedetomidine in pediatric cardiac transplant patients. METHODS: Twelve patients, aged 10 years or younger, weighing ≤40 kg, presenting for routine surveillance of right and left heart cardiac catheterization after cardiac transplantation were enrolled. After an inhaled or i.v. induction, the tracheas were intubated and anesthesia was maintained with 1 minimum alveolar concentration of isoflurane in room air, fentanyl (1 µg/kg), and rocuronium (1 mg/kg). At the completion of the planned cardiac catheterization, 100% oxygen was administered. After recording a set of baseline values that included heart rate (HR), systolic blood pressure, diastolic blood pressure, central venous pressure, systolic pulmonary artery pressure, diastolic pulmonary artery pressure, pulmonary artery wedge pressure, and thermodilution-based cardiac output, a rapid i.v. dexmedetomidine bolus of either 0.25 or 0.5 µg/kg was administered over 5 seconds. The hemodynamic measurements were repeated at 1 minute and 5 minutes. RESULTS: There were 6 patients in each group. Investigation suggested that systolic blood pressure, diastolic blood pressure, systolic pulmonary artery pressure, diastolic pulmonary artery pressure, pulmonary artery wedge pressure, and systemic vascular resistance all increased at 1 minute after rapid i.v. bolus for both doses and decreased significantly to near baseline for both doses by 5 minutes. The transient increase in pressures was more pronounced in the systemic system than in the pulmonary system. In the systemic system, there was a larger percent increase in the diastolic pressures than the systolic pressures. Cardiac output, central venous pressure, and pulmonary vascular resistance did not change significantly. HR decreased at 1 minute for both doses and was, within the 0.5 µg/kg group, the only hemodynamic variable still changed from baseline at the 5-minute time point. CONCLUSION: Rapid i.v. bolus administration of dexmedetomidine in this small sample of children having undergone heart transplants was clinically well tolerated, although it resulted in a transient but significant increase in systemic and pulmonary pressure and a decrease in HR. In the systemic system, there is a larger percent increase in the diastolic pressures than the systolic pressures and, furthermore, these transient increases in pressures were more pronounced in the systemic system than in the pulmonary system.

Transcatheter aortic valve implantation: durability of clinical and hemodynamic outcomes beyond 3 years in a large patient cohort.

BACKGROUND: Although short- and medium-term outcomes after transcatheter aortic valve implantation are encouraging, long-term data on valve function and clinical outcomes are limited. METHODS AND RESULTS: Consecutive high-risk patients who had been declined as surgical candidates because of comorbidities but who underwent successful transcatheter aortic valve implantation with a balloon-expandable valve between January 2005 and December 2006 and survived past 30 days were assessed. Clinical, echocardiographic, and computed tomographic follow-up examinations were performed. Seventy patients who underwent successful procedures and survived longer than 30 days were evaluated at a minimum follow-up of 3 years. At a median follow-up of 3.7 years (interquartile range 3.4 to 4.3 years), survival was 57%. Survival at 1, 2, and 3 years was 81%, 74%, and 61%, respectively. Freedom from reoperation was 98.5% (1 patient with endocarditis). During this early procedural experience, 11 patients died within 30 days, and 8 procedures were unsuccessful. When these patients were included, overall survival was 51%. Transaortic pressure gradients increased from 10.0 mm Hg (interquartile range 8.0 to 12.0 mm Hg) immediately after the procedure to 12.1 mm Hg (interquartile range 8.6 to 16.0 mm Hg) after 3 years (P=0.03). Bioprosthetic valve area decreased from a mean of 1.7±0.4 cm(2) after the procedure to 1.4±0.3 cm(2) after 3 years (P<0.01). Aortic incompetence after implantation was trivial or mild in 84% of cases and remained unchanged or improved over time. There were no cases of structural valvular deterioration, stent fracture, deformation, or valve migration. CONCLUSIONS: Transcatheter aortic valve implantation demonstrates good medium- to long-term durability and preserved hemodynamic function, with no evidence of structural failure. The procedure appears to offer an adequate and lasting resolution of aortic stenosis in selected patients.

Autologous hematopoietic stem cell transplants that utilize total body irradiation can safely be carried out entirely on an outpatient basis.

Outpatient hematopoietic stem cell transplants (HSCT) are usually performed in patients receiving minimally mucotoxic preparative regimens; total body irradiation (TBI)-based regimens typically are excluded. To improve resource utilization and patient satisfaction, we developed a totally outpatient HSCT program for TBI regimens and compared outcomes for our first 100 such transplants to 32 performed as in-patients during the same interval, for caregiver or financial reasons. Symptoms were managed predominately with oral agents; pain management consisted of transdermal fentanyl and oral morphine solution. Except for more unmarried in-patients, the two groups were matched. Time to engraftment, severity of mucositis and transplant duration were identical for the two groups. Twenty-seven of the outpatients were admitted (median-6 days), primarily for progressing infection. Thus 92% of all transplant days were outpatient. There were no septic episodes or hospital admissions for pain management. There were no deaths to day 30 in either group and 100-day survival was identical. There was a mean cost savings of Dollars 16,000 per outpatient transplant and outpatient patient/caregiver quality of life was similar to that reported for in-patients. Patients undergoing severely mucotoxic regimens can be safely transplanted in an outpatient setting with a significant cost saving, with no increase in morbidity or mortality.

Patients' understanding of disease status and treatment plan at initial hematopoietic stem cell transplantation consultation.

Patients referred for hematopoietic stem cell transplantation (HSCT) often have knowledge deficits about their disease and overestimate their prognosis making it difficult initially to discuss potentially life-threatening transplant options. To determine patients' understanding of their disease and the adequacy of a 3-h consultation at our center, we developed a survey that measured perceived knowledge deficits of disease, prognosis, and emotional status before and after their initial consultation. Ninety nine consecutive eligible patients completed the survey. Although 76.7% claimed adequate information about their disease pre-HCST visit, 51.5 and 41.4% respectively lacked knowledge about their 1-year prognosis with and without any therapy. After the visit, 66.7% of the patients had obtained enough information to make an informed decision regarding HSCT versus 23.2% pre-visit, and a significant reduction in the need for further information was reported by 53.5% of patients (P<0.001). Patients were not overwhelmed or confused by the visit and there was a small but significant decrease in negative affect. Measures to increase patients understanding of their disease and its prognosis pre-HSCT consultation visit are warranted; however, a 3-h consultation visit provides the majority of patients with sufficient information to make an informed decision about the risk/benefit ratio of HSCT.

Reduction of postprandial hyperglycemia in patients with type 2 diabetes reduces NF-kappaB activation in PBMCs.

AIMS/HYPOTHESIS: Short-lasting hyperglycemia results in activation of the transcription factor NF-kappaB in peripheral blood mononuclear cells. We therefore studied whether the postprandial increase in glucose is sufficient to induce mononuclear NF-kappaB activation and whether blunting postprandial hyperglycemia with the alpha-glucosidase inhibitor acarbose reduces NF-kappaB activation. METHODS: 20 patients with type 2 diabetes were included in a double-blind randomized trial receiving 100 mg acarbose or placebo three times a day over a period of eight weeks. Peripheral blood mononuclear cells were isolated before and 120 minutes after a standardized breakfast. NF-kappaB binding activity was estimated by electrophoretic mobility shift assay and NF-kappaB-p65; translocation was determined by Western blot. RESULTS: Eight weeks of treatment with acarbose significantly reduced postprandial hyperglycemia (p = 0.004 when compared to placebo), postprandial mononuclear NF-kappaB-binding activity (p = 0.045) and nuclear translocation of NF-kappaB-p65 (p = 0.02). CONCLUSION: Reduction of postprandial glucose peak levels by acarbose reduces postprandial mononuclear NF-kappaB activation.

Automated distal coronary bypass with a novel magnetic coupler (MVP system).

OBJECTIVE: We sought to assess the feasibility of performing sutureless distal coronary artery bypass anastomoses with a novel magnetic coupling device. METHODS: From May 2000 to April 2001, single-vessel side-to-side coronary artery bypass grafting on a beating heart was performed in 39 domestic white pigs (35-60 kg) without the use of mechanical stabilization, shunts, or perfusion bridges. Animals were divided into 2 groups. Seventeen pigs underwent right internal thoracic artery to right coronary artery bypass grafting through a median sternotomy (group 1) with a novel magnetic vascular positioning system (MVP system; Ventrica, Inc, Fremont, Calif). Twenty-two pigs underwent left internal thoracic artery to left anterior descending artery grafting with the MVP anastomotic device through a left anterior minithoracotomy (group 2). This system consists of 2 pairs of elliptical magnetic implants and a deployment device. One pair of magnets forms the anastomotic docking port within the graft; the other pair forms an identical anastomotic docking port within the target vessel. The anastomosis is created when the 2 docking ports magnetically couple. Anastomotic patency was evaluated by means of angiography during the first postoperative week and at 1 month. Histologic studies were performed at different time points as late as 6 months. RESULTS: Right internal thoracic artery to right coronary artery anastomoses and left internal thoracic artery to left anterior descending artery anastomoses were successfully performed with the system in all animals. The self-adherent and self-aligning properties of the implants allowed for immediate and secure approximation of the arteries (total anastomotic time between 2-3 minutes). Anastomoses were constructed without a stabilization platform. Five nondevice-related deaths occurred postoperatively. One-week angiography, performed in 35 surviving animals, showed a patent graft and anastomosis in all cases. The patency rate at 1 month was 97% (33/34). Histologic studies as late as 6 months demonstrated neointimal coverage of the magnets without any significant luminal obstruction. Histology also confirmed the presence of viable tissue between magnets. CONCLUSION: The MVP anastomotic system uses magnetic force to create rapid and secure distal coronary artery anastomoses, which might facilitate minimally invasive and totally endoscopic coronary artery bypass surgery.

Re-operation for bioprosthetic aortic structural failure - risk assessment.

OBJECTIVE: The predominant complication of bioprostheses is structural valve deterioration and the consequences of re-operation. Prosthesis choice for aortic valve replacement surgery (bioprostheses and mechanical prostheses), is influenced by valve-related complications (mortality and morbidity) of the prosthesis type chosen. The purpose of the study is to determine the mortality and risk assessment of that mortality for aortic bioprosthetic failure. METHODS: From 1975 to 1999, 3356 patients received a heterograft bioprosthesis in 3530 operations. The procedures were performed with concomitant coronary artery bypass (CAB) in 1388 procedures and without in 2142 procedures. Three hundred twenty-two re-operations for structural valve deterioration were performed in 312 patients with 22 fatalities (6.8%). Of the 322 re-replacements, 36 had CAB and 286 had isolated replacement; the mortality was 8.3% (3) and 6.6% (19), respectively. Eleven predictive factors inclusive of age, concomitant CAB, urgency status, New York Heart Association (NYHA) at Re-op and year of Re-op (year periods) were considered. RESULTS: The mortality for 1979-1986 was 6.1% (2/33); 1987-1992, 7.7% (8/104); and 1993-2000, 6.5% (12/185) (pNS). The mortality by urgency status for elective/urgent was 6.4% (19/299); and emergent, 13.0% (3/23) (pNS). The mortality for NYHA I/II was 2.0% (1/50), III 4.2% (8/191) and IV 16.0% (13/81) (P=0.00063), for gender was male 4.6% and female 13.3% (P=0.011), for age at implant 'No' (no re-operation) 51.6+/-12.2 years and 'Yes' (yes re-operation) 59.9+/-7.3 years (P=0.00004), for age at explant 'No' 62.6+/-12.7 years and 'Yes' 70.6+/-6.5 years (P=0.00001), and for age at explant <60 years 0.0% (0/110), 60-70 years 8.5% (10/117) and >70 years 12.6% (12/95) (P=0.0011). The predictive risk factor assessment by multivariate regression analysis revealed only NYHA III Odds Ratio 1.7 and IV 7.8 P=0.0082. For the period 1993-2000 of re-operations only gender was significant; age at implant, age at explant, CAB pre-Re-op, CAB concomitant with Re-op, urgency at Re-op, ejection fraction, valve lesion and NYHA at Re-op were not significant. CONCLUSIONS: Bioprosthetic aortic re-operative mortality can be lowered by re-operation in low rather than medium to severe NYHA functional class. The routine evaluation of patients can achieve earlier low risk re-operative surgery.

Reoperation for bioprosthetic mitral structural failure: risk assessment.

BACKGROUND: The predominant complication of bioprostheses is structural valve deterioration and the consequences of reoperation. The purpose of the study was to determine the mortality and risk assessment of that mortality for mitral bioprosthetic failure. METHODS AND RESULTS: From 1975 to 1999, 1 973 patients received a heterograft bioprosthesis in 2 152 operations. The procedures were performed with concomitant coronary artery bypass (CAB) in 694 operations and without in 1 458 operations. There were 481 reoperations for structural valve deterioration performed in 463 patients with 34 fatalities (7.1%). Of the 481 re-replacements, 67 had CAB and 414 had isolated replacement; the mortality was 11.9% (8) and 6.3% (26), respectively. Eleven predictive factors inclusive of age, concomitant CAB, urgency status, New York Heart Association (NYHA; reoperation), and year of reoperation (year periods) were considered. The mortality from 1975 to 1986 was 9.8% (6/61), from 1987 to 1992 it was 10.8% (20/185), and from 1993 to 2000 it was 3.4% (8/235) (I versus III P=0.0458, II versus III P=0.0047). The mortality by urgency status was elective/urgent 6.0% (26/436) and emergent 17.8% (8/45) (P=0.00879). The mortality was NYHA I/II 0.00% (0/37), III 5.1% (14/273), and IV 11.7% (20/171) (P=0.0069). The predictive risk factors by multivariate regression analysis were age at implant, odds ratio (OR) 0.84 (P=0.0113); age at explant, OR 1.2 (P=0.0089); urgency, OR 2.8 (P=0.0264); NYHA, OR 2.5 (P=0.015); 1975-1986 versus 1993-2000 of reoperations, OR 5.8 (P=0.0062); and 1987-19 92 versus 1993-2000, OR 4.0 (P=0.0023). For the period 1993 to 2000 of reoperations, only age at implant and age at explant were significant; NYHA class, urgency status, and concomitant CAB were not significant. CONCLUSIONS: Bioprosthetic mitral reoperative mortality can be lowered by reoperations on an elective/urgent basis in low to medium NYHA functional class. The routine evaluation of patients can achieve earlier low risk reoperative surgery.

Incidence, predictors, and significance of abnormal cardiac enzyme rise in patients treated with bypass surgery in the arterial revascularization therapies study (ARTS).

BACKGROUND: Although it has been suggested that elevation of CK-MB after percutaneous coronary intervention is associated with adverse clinical outcomes, limited data are available in the setting of coronary bypass grafting. The aim of the present study was to determine the incidence, predictors, and prognostic significance of CK-MB elevation following multivessel coronary bypass grafting (CABG). METHODS AND RESULTS: The population comprises 496 patients with multivessel coronary disease assigned to CABG in the Arterial Revascularization Therapies Study (ARTS). CK-MB was prospectively measured at 6, 12, and 18 hours after the procedure. Thirty-day and 1-year clinical follow-up were performed. Abnormal CK-MB elevation occurred in 61.9% of the patients. Patients with increased cardiac-enzyme levels after CABG were at increased risk of both death and repeat myocardial infarction within the first 30 days (P=0.001). CK-MB elevation was also independently related to late adverse outcome (P=0.009, OR=0.64). CONCLUSIONS: Increased concentrations of CK-MB, which are often dismissed as inconsequential in the setting of multivessel CABG, appear to occur very frequently and are associated with a significant increase in both repeat myocardial infarction and death beyond the immediate perioperative period.

Potential deleterious effect of beta-adrenergic stimulation during warm-blood cardioplegia in rabbit hearts.

We hypothesized that beta-adrenergic stimulation with isoproterenol during continuous normothermic cardioplegic arrest would enhance the regenerative and regulatory function of the myocardium, resulting in improved cardiac function. We studied isolated rabbit hearts paced at approximately 200 beats per minute (bpm) and perfused by a support rabbit. We measured ventricular pressure over a range of ventricular volumes to determine maximal elastance (Emax) at baseline and 20 and 45 min after discontinuation of cardioplegia. Myocardial oxygen consumption (MVO2) measurements were performed simultaneously and during cardioplegic arrest. Hearts were prospectively randomized to receive either isoproterenol at 0.1 M or control in blinded fashion for 10 min during a 1-h continuous warm-blood cardioplegic arrest. Compared to control hearts, isoproterenol-treated hearts had trends toward longer time to first spontaneous heartbeat (control 141 +/- 43 vs. isoproterenol 200 +/- 74 s, p = .07), and longer time to capture of atrial pacing (control 214 +/- 52 vs. isoproterenol 288 +/- 91 s, p = .06). There was no difference observed in the MVO2 between isoproterenol-treated and control groups of hearts. MVO2 decreased during cardioplegia (p < .01), but there was no significant change in MVO2 during isoproterenol infusion during cardioplegic arrest. There was a significant reduction in Emax compared to baseline 20 min after discontinuation of cardioplegic arrest in both groups (control 7.3 +/- 1.7 mm Hg/microL vs. 9.0 +/- 1.7 mm Hg/microL, p = .02, isoproterenol-treated 6.8 +/- 2.8 mm Hg/microL vs. 8.2 +/- 2.6 mm Hg/microL, p = .01, respectively), with recovery of Emax by 45 min in control hearts only. We conclude that exposure of hearts to isoproterenol during warm cardioplegic arrest has a deleterious effect that may be mediated through mechanisms independent of increased myocardial oxygen consumption.

[Long-term weight reduction. Current therapy approaches in obesity]. / Langfristig abnehmen. Aktuelle Therapieansätze bei Adipositas.

A large percentage of obese patients can lose weight with a combination of various dietary measures. The following possibilities are available: 1. The fat-reduced, carbohydrate-enhanced diet. 2. Formula diets, which are applied when a mixed diet has failed, or, alternatively, as an "introduction" to a weight-reducing program. In addition, suitable exercise programs and behavior-modifying measures aimed at stabilizing weight losses over the long-term, are also recommended. If this basic program fails, adjunctive drug treatment is indicated. Surgical treatment may be considered when various conservative forms of treatment have proved unsuccessful over a period of years.

Heat-sensitive conduction block in ulnar neuropathy at the elbow.

OBJECTIVES: To study the effects of elbow heating on conduction block (CB) and across-elbow conduction velocity (CV) in patients with ulnar neuropathy at the elbow (UNE). METHODS: We studied 15 patients with UNE, performing motor nerve conduction studies at 32 degrees C and after heating the elbow to 42 degrees C. RESULTS: At 32 degrees C, mean response amplitude and area with above-elbow (AE) stimulation were 20.4 and 16.0% lower than with below-elbow (BE) stimulation, respectively. With heating the elbow to 42 degrees C, these differences increased significantly to 28.9 and 26.9% (P=0.019 and 0.029), respectively. The mean CV reduction in the across-elbow segment relative to the forearm segment also increased from 20.5 m/s at 32 degrees C to 25.6 m/s at 42 degrees C (P=0.0010). Across-elbow CV at 32 degrees C correlated with increased CB (as measured by amplitude) with heating (r=0.53, P=0.048) and approached significance for area (r=0.48, P=0.068) Likewise, baseline CB at 32 degrees C correlated with the likelihood of increased CB for amplitude (r=0.77, P<0.001), and approached significance for area (r=0.47, P=0.079). CONCLUSIONS: Elbow heating in UNE increases the relative drop in across-elbow CV and the degree of across-elbow CB; absolute across-elbow CV and the presence of baseline CB at 32 degrees C are good predictors of this latter effect.

Late results of the Warm Heart Trial: the influence of nonfatal cardiac events on late survival.

BACKGROUND: The Warm Heart Trial randomized 1732 CABG patients to receive warm or cold blood cardioplegia. In the warm cardioplegia patients, nonfatal perioperative cardiac events were significantly decreased and the mortality rate was nonsignificantly decreased (1. 4% versus 2.5%, P:=0.12). The purpose of the present study was to evaluate the late results of these trial patients. METHODS AND RESULTS: Randomization was stratified according to surgeon and urgency of the operation. Seven hundred sixty-two patients recruited from 1 of the centers were followed through the hospital clinic for late events. Late survival (including perioperative deaths) at 72 months was nonsignificantly greater in the warm cardioplegia patients (94.5+/-1.7%, mean+/-SEM) than in the cold cardioplegia patients (90.9+/-2.6%). Independent predictors of mortality by Cox proportional hazards model were redo CABG, diabetes mellitus, renal insufficiency, and increasing age. The influence of nonfatal perioperative events (perioperative myocardial infarction according to computerized ECG readings or low output syndrome as determined by an outcome committee) on late survival was also analyzed. Late survival at 84 months was significantly reduced in the group who experienced nonfatal perioperative outcomes (94.5+/-1.7% versus 84. 9+/-4.5%, P:<0.001) and remained a significant predictor after adjustment for other important variables (risk ratio 6.4, 95% CI 1. 87 to 8.73, P:<0.0001). CONCLUSIONS: Effective myocardial protection through either cold or warm blood cardioplegia is essential, because late survival is significantly reduced in patients with nonfatal perioperative cardiac outcomes.

Carpentier-Edwards porcine bioprostheses: clinical performance assessed by actual analysis.

BACKGROUND AND AIM OF THE STUDY: The clinical performance of porcine bioprostheses for valve replacement has been evaluated for over three decades by actuarial analysis as the standard for reporting time-related results. Actual or cumulative incidence analysis provides a complementary method to determine the manifestations of valve-related complications due primarily to structural valve deterioration. Valve-related mortality and reoperation of porcine bioprostheses for aortic and mitral valve replacement was compared by actuarial and actual methodology. METHODS: The Carpentier-Edwards porcine bioprostheses were implanted between 1975 and 1995 as 2,237 aortic valve replacements (AVR) and 1,582 mitral valve replacements (MVR). Coronary artery bypass was performed in 36.4% of AVR, and 30.6% of MVR. Fatal valve-related complications occurred in 7.6% of AVR and 11.3% of MVR. The cumulative follow up was 14,810 patient-years (mean 6.6 years) for AVR and 9,718 patient-years (mean 6.1 years) for MVR. RESULTS: Patient survival, and actuarial and actual freedom from valve-related mortality and valve-related reoperation was reported at 15 years. For AVR, survival in the 61-70 years age group was 30.9%, freedom from valve-related mortality was 79.3% and 86.9% respectively, and freedom from valve-related reoperation 79.0% and 88.1% respectively. For AVR, survival in the >70 years age group was 18.1%, freedom from valve-related mortality 72.8% and 84.9% respectively, and freedom from reoperation 86.3% and 96.1% respectively. For MVR, survival in the 61-70 years age group was 16.1% at 15 years, freedom from valve-related mortality was 59.5% and 79.5% respectively, and freedom from valve-related reoperation 32.6% and 71.0% respectively. For MVR, survival in the >70 years age group was 2.8% at 15 years, valve-related mortality was 26.1% and 82.0% respectively, and freedom from valve-related reoperation 83.4% and 93.3% respectively. CONCLUSION: The actual freedom from valve-related mortality and valve-related reoperation (primarily from structural valve deterioration), provides further evidence to consider porcine bioprostheses for AVR in patients aged >60 years, and for MVR in patients aged >70 years. The freedom from valve-related mortality supports the use of porcine bioprostheses for MVR in patients aged 61-70 years. Patient survival is influenced to the greatest extent by factors other than valve-related mortality.

The role of hepatic resection in the management of bile duct injuries following laparoscopic cholecystectomy.

The creation of a specialized hepatobiliary surgery unit at our medical center has resulted in referral of 16 patients with bile duct complications following laparoscopic cholecystectomy over the last 18 months. No patient required conversion to open cholecystectomy. Although no injury was recognized at the time of surgery, 15 of 16 patients became symptomatic within the first 30 days. Two patients died from sepsis and multisystem organ failure after protracted hospital courses. Endoscopic retrograde cholangiopancreatography and/or percutaneous transhepatic cholangiography determined diagnosis and level of injury. Six of seven patients with cystic duct leak underwent successful endoscopic stent placement and one patient sealed spontaneously after percutaneous drainage of a large biloma. Nine patients required surgery that included hepaticojejunostomy (five), T-tube insertion and drainage of abscess (two), or segmental hepatic resection (two). Timely recognition of bile duct complications following laparoscopic cholecystectomy is critical to a successful long-term outcome. Although the majority of cystic duct leaks can be managed with endoscopic stenting, patients with ductal injuries require hepaticojejunostomy. Segmental liver resection may serve an important role in the management of carefully selected patients with high intrahepatic injuries to avoid long-term transhepatic stenting and complications such as episodic cholangitis and late stricture formation.

Randomized controlled trial to determine the safety and efficacy of a multi-cell pulsating dynamic mattress system in the prevention of pressure ulcers in patients undergoing cardiovascular surgery.

The purpose of this study was to determine the efficacy and safety of a multi-cell pulsating dynamic mattress system in comparison with conventional management for the prevention of pressure ulcers in the operative and postoperative period in patients having cardiovascular surgery. The study was a single center, prospective, randomized, controlled trial. Patients who were having cardiovascular surgery for a duration of at least 4 hours were randomly assigned, prior to surgery, to dynamic mattress system or conventional management--both of which were initiated in the operating room and continued for up to 7 days postoperatively. Patients were assessed daily using a standardized scoring system. The results of the study showed that 198 patients in the dynamic pressure system (n = 98) or conventional management group (n = 100) were similar at baseline. A strong trend of decreased pressure ulcers existed in the dynamic pressure system group (n = 2) compared to the conventional management group (n = 7). The study concluded that a multi-cell pulsating dynamic mattress system is safe and mitigates risks for and decreases incidence of pressure ulcers in patients who undergo cardiovascular surgery.

The pulmonary venous systolic flow pulse--its origin and relationship to left atrial pressure.

OBJECTIVES: The purpose of this study was to determine the origin of the pulmonary venous systolic flow pulse using wave-intensity analysis to separate forward- and backward-going waves. BACKGROUND: The mechanism of the pulmonary venous systolic flow pulse is unclear and could be a "suction effect" due to a fall in atrial pressure (backward-going wave) or a "pushing effect" due to forward-propagation of right ventricular (RV) pressure (forward-going wave). METHODS: In eight patients during coronary surgery, pulmonary venous flow (flow probe), velocity (microsensor) and pressure (micromanometer) were recorded. We calculated wave intensity (dP x dU) as change in pulmonary venous pressure (dP) times change in velocity (dU) at 5 ms intervals. When dP x dU > 0 there is a net forward-going wave and when dP x dU < 0 there is a net backward-going wave. RESULTS: Systolic pulmonary venous flow was biphasic. When flow accelerated in early systole (S1), pulmonary venous pressure was falling, and, therefore, dP x dU was negative, -0.6 +/- 0.2 (x +/- SE) W/m2, indicating a net backward-going wave. When flow accelerated in late systole (S2), pressure was rising, and, therefore, dP x dU was positive, 0.3 +/- 0.1 W/m2, indicating a net forward-going wave. CONCLUSIONS: Pulmonary venous flow acceleration in S1 was attributed to a net backward-going wave secondary to a fall in atrial pressure. However, flow acceleration in S2 was attributed to a net forward-going wave, consistent with propagation of the RV systolic pressure pulse across the lungs. Pulmonary vein systolic flow pattern, therefore, appears to be determined by right- as well as left-sided cardiac events.

Bileaflet mechanical prostheses performance in mitral position.

OBJECTIVE: The experience with the Carbomedics (CM) and the St. Jude Medical (SJM) bileaflet mechanical prostheses was evaluated to determine thromboembolic and hemorrhagic complications and predictive risk factors. METHODS: From 1989 to 1994, a total of 625 patients had mitral valve replacement (CM, 240; SJM, 385); 32.5% (203), concomitant procedures and 32.8% (205), previous cardiac surgery, primarily valve replacement procedures. RESULTS: The pre-operative variables did not distinguish the populations, except for previous surgery CM 37.9% and SJM 29.6% (P < 0.05). The pre-operative variables (type of prostheses, cardiac rhythm, coronary artery bypass, NYHA III/IV, advancing age, gender, urgency status and previous surgery) were not predictive of overall thromboembolism (TE), major TE, minor TE, prosthesis thrombosis and hemorrhage (P not significant; P = NS). The linearized rate of total TE events for overall MVR was 5.0%/patient-year (CM 4.4; SJM 5.4). The < or = 30 day major crude rate was 0.44%, while the > 30 day late major event rate was 2.0%/patient-year. Of the total TE events 91% of < or = 30 days and 75%, > 30 days had an INR < 2.5 at or immediately prior to the event. The thrombosis rate (included in TE events) was 0.63%/patient-year (ten events, four managed successfully with thrombolysis, five successfully with reoperation, and one fatality identified at autopsy). The freedom, at 5 years, from major/fatal TE, thrombosis and hemorrhage from anticoagulation was 88.2%, and 89.5% exclusive of early events. CONCLUSIONS: This non-randomized prospective observational evaluation of the CarboMedics and St. Jude Medical prostheses has not revealed any differentiation in performance of the prostheses. The study serves as a single institution experience with the potential for future comparative evaluation.