E. Gutiérrez

Relaparotomy After Pancreas Transplantation: Causes and Outcomes

INTRODUCTION Surgical complications after pancreas transplantation, and subsequently relaparotomies, are frequently associated with graft loss, important morbidities, and occasionally patient death. PATIENTS AND METHODS From March 1995 to September 2008, 118 diabetic patients underwent pancreas transplantation: 109 simultaneous pancreas-kidney and nine pancreas after kidney. There were 68 men and 50 women. Mean age at transplantation was 37.8 +/- 7.8 years (range = 25-66). We analyzed donor and recipient characteristics, rate of relaparotomies, risk factors, as well as patient and graft survivals. RESULTS Forty patients (33.9%) underwent one or more relaparotomies. The causes for relaparotomy were: graft thrombosis in 15 patients (12.7%), bleeding in 14 (11.9%), duodenal stump leak in 7 (5.9%), severe pancreatitis and/or abscess in 5 (4.2%), and small bowel obstruction in 3 (2.5%). Graft pancreatectomy was performed in 52.5% (21 patients). The causes of graft loss were: graft thrombosis in 15 patients (12.7%), bleeding in 14 (11.9%), and duodenal stump leaks in 7 (5.9%). Mortality rate after relaparotomy was 3.38% (four patients). Relaparotomy rate for thrombosis was higher among the portoiliac than the portocaval vein anastomosis group (20.0% vs 10.2%; P = NS), and significantly higher for the bladder drainage than the enteric drainage technique (18.2% vs 5.8%; P < .05). Patients without relaparotomy experienced a significantly higher 5-year graft survival rate than those who underwent relaparotomy (87.2% vs 37.9%; P < .001), but 5-year patient survivals were similar (96.8% without relaparotomy vs 89.6% with relaparotomy). CONCLUSIONS Abdominal complications and the necessity for relaparotomy were associated with important morbidity and significantly reduced pancreas graft survival.

Renal Allograft Function and Cardiovascular Risk in Recipients of Kidney Transplantation After Successful Pregnancy

Successful pregnancy is one of the better indicators of quality of life for women who are of child-bearing age with restored fertility after kidney transplantation. Our objective was to evaluate whether pregnancy represented a risk factor for worsening of renal function or for cardiovascular disease among renal transplant recipients. From 1976 to 2007, we followed 30 successful pregnancies in 27 renal recipients in our hospital; three women had two twin gestations. We compared this population with 27 women with renal transplants who were not pregnant. They were of similar ages at transplantation (pregnant 31.1 +/- 5.4 years vs not pregnant 31.3 +/- 5.4 years, P = NS) and similar evolution time between kidney transplantation and pregnancy (51.5 +/- 36 months vs 47.2 +/- 41 months respective; P = NS). There were no acute rejection episodes or graft losses. Renal function measured by serum creatinine and MDRD4 at the end of pregnancy was lower among the pregnant compared with the control group: mainly, 1.1 +/- 0.2 mg/dL versus 0.9 +/- 0.2 mg/dL (P = .05), and 66 +/- 20 mL/min/1.73 m(2) versus 80 +/- 26 mL/min/1.73 m(2) (P = .03). At 1 and 10 years, renal function was similar among the groups. Ten pregnant women developed preeclampsia (37%) and three, gestational diabetes mellitus (11%). There was one major cardiovascular event (4%; acute myocardial infarction) among the pregnant group, whereas there were two in the control group (7.4%; stroke and severe hypertensive retinopathy). One death occurred in each group secondary to cardiovascular complications. Our results showed that successful pregnancy after renal transplantation did not represent a long-term risk factor to worsen renal function and or produce severe cardiovascular complications. Therefore, pregnancy should be promoted. for young women with renal transplants that show excellent function.

Compative study of bladder versus enteric drainage in pancreas transplantation.

INTRODUCTION There is some controversy concerning the choice of best technique for drainage of exocrine secretions in pancreas transplantation. We compared patients with bladder drainage (BD) versus those with enteric drainage (ED). PATIENTS AND METHODS From March 1995 to September 2008, 118 patients (68 men and 50 women) of overall mean age of 37.8 +/- 7.8 years underwent pancreas transplantation. There were 109 simultaneous pancreas-kidney, and 9 pancreas after kidney procedures. Recipients were divided in a BD (n = 66 patients) and an ED group (n = 52). RESULTS Donor characteristics were similar in both groups. Thirty-two patients (48.5%) of the BD group versus none in the ED group experienced urinary tract infections (UTI; P < .001), and 16 patients (24.2%) BD versus 15 (29.4%) ED developed intraabdominal infections (P = NS). The overall rate of relaparotomies was 33.9% (n = 40): 34.8% (n = 23) in the BD versus 32.7% (n = 17) in the ED group (P = NS). Thirty patients (25.4%) lost their pancreas grafts: 21 (31.8%) in the BD group versus 9 (17.3%) in the ED group (P = .055). The acute rejection rates were 12.7%; namely, 15.2% in the BD versus 9.8% in the ED (P = NS). Three-year patient and graft survivals were equivalent in both groups: 96.1% and 65.3% in the BD versus 89.0% and 74.0% in the ED group, respectively (P = NS). CONCLUSIONS ED is a good alternative to BD for drainage of pancreatic graft exocrine secretions because both techniques have the same patient and graft survival, but BD is associated with a significantly higher rate of UTI and urologic complications.

Extended-Release Tacrolimus Therapy in De Novo Kidney Transplant Recipients: Single-Center Experience

BACKGROUND Available data for extended-release tacrolimus (Tac) except in clinical trials are limited. OBJECTIVE To describe our initial experience with once-daily Tac in combination with corticosteroids and mycophenolate mofetil therapy in patients undergoing de novo renal transplantation. PATIENTS AND METHODS In this retrospective, observational, single-center study, data were obtained for 49 adult recipients treated with extended-release Tac and 30 patients treated with standard-release Tac (control group). Mean (SD) follow-up in the 2 groups was 3.5 (2.5) months and 4.0 (2.6) months, respectively. The primary characteristics were comparable between the groups. RESULTS The acute rejection rate in the extended-release group was 10%, and 13% in the standard-release group. Patient and graft survival rates were 98% and 96% vs 100% and 90%, respectively. Renal function in the 2 groups was comparable: serum creatinine concentration 1.3 (0.2) mg/dL vs 1.45 (0.4) mg/dL. At day 14 posttransplantation, Tac doses were 0.17 mg/kg/d vs 0.14 mg/kg/d, and blood concentrations were 9.0 ng/mL vs 14.0 ng/mL. In recipients older than 60 years, lower dosages of Tac resulted in blood concentrations similar to those in younger patients, with less variation in dosage. CONCLUSIONS Short-term experience with extended-release Tac therapy in de novo renal recipients confirms its efficacy and safety. Adjusting blood concentrations in the immediate posttransplantation period is less difficult with extended-release Tac compared with the twice-daily formulation.

Experimental Design and Analysis of a Gyroelastic Beam

Gyroscopic systems and their properties have been extensively studied as Angular Momentum Devices (AMD), Control Moment Gyros (CMG) or Gyroscopes for various applications such as structure control, stability or energy storage. However, most of the works that have been done are theoretical and do not present experimental implementation. In this work we performed an experimental study of a gyroscope beam system (gyroelastic beam) focused systems on the deflection of cantilever beams or the control of flexural stresses. We first used a simple two-degree of freedom model to better understand the terms governing the design, construction and experimental evaluation of gyroelastic beam systems. We then performed experimental tests at different velocities of the gyroscopic actuator and measured the deflection of the system. The results showed that it is possible to have control of the deflection and the bending forces for this type of configurations which can be exported to helicopter blades or wind turbine blades.