Biomedical subjects

J M Díaz

Publications and source records attributed to J M Díaz.

At least 19 recordsLinked to original sources

PubMed2006

Assessment of the arteries in living kidney donors: correlation of magnetic resonance angiography with intraoperative findings.

Comprehensive imaging evaluation of kidney donor anatomy is crucial for selecting candidates for living kidney transplantation and for determining the surgical technique to procure the renal graft. In 76 living renal donors we compared the results of preoperative magnetic resonance angiography (MRA) with the intraoperative findings of arterial anatomy. Donors were evaluated for the number of main renal arteries and the presence of any polar arteries. A total of 80 main renal arteries and five polar arteries were observed at MRA. At surgery, 90 main renal arteries and eight polar arteries were identified. MRA demonstrated a sensitivity, specificity, and overall accuracy of 18%, 98%, and 87%, respectively, for main arteries and 25%, 96%, and 88% for polar arteries. Eleven (14.5%) kidneys displayed more than one main artery and MRA only detected two cases. Eight kidneys had polar arteries and MRA only detected two cases. MRA is a reliable method for presurgical evaluation of renal arteries in potential donors, providing valuable information required by the surgeon. But, as the technique misses small-diameter vessels, it cannot be recommended as the sole diagnostic tool in unclear cases.

Adult↗

PubMed2005

Percutaneous management of transplant ureteral fistulae is feasible in selected cases.

INTRODUCTION: Ureteral fistulae in renal transplants may develop as a consequence of compromised ureteral vascularity or from a technical factor related to the ureteroneocystostomy, the latter typically developing within the first 72 hours posttransplant. Recently, percutaneous nephrostomy drainage has been used with increasing frequency for the initial management. It alone can lead to resolution of the fistula in at least some patients. The aim of the study was the evaluation of endourological management of ureteral fistulae in renal transplants. MATERIAL AND METHODS: Between August 1981 and February 2004, 1000 adult recipients underwent renal transplantation. Sixteen out of 29 patients who developed ureteral fistulae were managed endourologically; 13, open surgery. The items recorded on these patients included the type of ureteroneocystostomy, the time to fistula diagnosis, the image technique, the type of ureteral stents, and the clinical evolution. RESULTS: The 13 patients who underwent open surgery did well. Endourological management of ureteral fistula was successfully performed in 10 of 16 cases. In all of them percutaneous nephrostomy drainage with stenting of the ureter with a double-J catheter did not prove any advantage to no stent (66.6% vs 57%). In 13 of these 16 patients in which the passage of contrast into the bladder was demonstrated, the fistula resolved in 10 cases (77%), while none of the three cases with no flow into the bladder were helped by this approach. CONCLUSION: Percutaneous techniques can provide definitive management for 62% of renal allograft patients who develop ureteral fistula beyond 72 hours after renal transplant.

Adult↗

PubMed2005

Cardiovascular risk factors in diabetic patients with renal transplants.

There is a progressive increase in cardiovascular events post-renal transplantation and diabetes mellitus (DM) is one of the major cardiovascular risk factors. The objective of this study was to analyze the prevalence of cardiovascular risk factors and nonfatal cardiovascular events among renal transplant recipients, according to the status of their carbohydrate metabolism. We studied 214 renal transplant recipients, among whom 18% diabetic and 82% were nondiabetic. The 16% prevalence of cardiovascular events were higher among the posttransplantation DM (PTDM) group (33%) compared with the other groups, 19% in pre-renal transplantation DM, 17% in altered baseline glycemia, and 13% in normal patients. Diabetic renal transplant recipients showed a greater prevalence of pretransplantation ischemic cardiopathy when they were older and had a higher pretransplantation body mass index (BMI) a heavier smoking habit, significantly increased microinflammation markers, and a greater need for antihypertensive and hypolipidemic treatment. Renal transplant recipients with altered baseline glycemia show greater BMI after transplantation, as well as higher Hb1Ac than patients with normoglycemia.

Blood Pressure↗

PubMed2005

Relation between pp65 antigenemia, RT-PCR and viruria for cytomegalovirus detection in kidney transplant recipients.

INTRODUCTION: We compared the efficiency of detection using pp65 antigenemia, reverse transcription-polymerase chain reaction (RT-PCR), and viruria for the diagnosis of cytomegalovirus (CMV) infections after kidney transplantation. PATIENTS AND METHODS: We evaluated 40 renal transplant recipients between weeks 5 and 12 after transplantation, including 179 blood and 181 urine specimens. RESULTS: All positive samples by antigenemia were also positive by PCR. However, in 52 cases only PCR was positive (kappa = 0.134 [P < .001]). Viruria was positive in 66 cases, but only 26 were CMV PCR positive. In 34 cases, viruria was negative and PCR positive (P = .192). CONCLUSION: Detection of DNA in serum is a more sensitive method than antigenemia for the diagnosis of CMV infection. Viruria was not related to the presence of CMV in blood.

Antigens, Viral↗

PubMed2005

Results and complications of 50 laparoscopic nephrectomies for live donor renal transplantation.

Living donors represent 30% of kidneys for renal transplantation. Laparoscopic nephrectomy is the best surgical procedure due to its clear advantages: low morbidity, less blood transfusion requirements, and shorter donor hospitalization. From March 2002 to August 2004, we performed 50 laparoscopic nephrectomies for transplantation to recipients who were prescribed tacrolimus (0.1 mg/kg bid), mycophenolate mofetil (1 gr bid), and prednisone (0.5-1 mg/kg per day PO from 48 hours before transplantation). Mean surgery time was 170 minutes (120-260); warm ischemia time, 3.1 minutes (1.5-10); and cold ischemia time, 1.27 hours (0.85-4). Mean bleeding was 270 cc (100-900), and mean donor hospitalization was 5.5 days (3-9). Four cases required conversion of the laparoscopic procedure to open surgery because of bleeding. Seventy-two hours posttransplantation, the mean plasma creatinine was 170 micromol/L. None of the patients suffered delayed graft function. Eighteen percent experienced acute rejection episodes. Donor and recipient survivals were 100% at 1 year, and graft survival, 94% (kidney losses were due to acute rejection, severe acute pancreatitis, and surgical complications).

Employment↗

PubMed2005

Endourological management is better in early-onset ureteral stenosis in kidney transplantation.

INTRODUCTION: The incidence of ureteral stenosis in kidney transplant recipients is 3%-8%. The treatment of ureteral stenosis has been traditionally operative reconstruction, although such intervention is associated with high rates of serious complications, including graft loss and even perioperative mortality. More recently, endourological treatment has been proposed due to its low morbidity. OBJECTIVE: The objective of this study was to assess the usefulness of balloon percutaneous dilatation as a treatment technique for ureteral stenosis in kidney transplant recipients. PATIENTS AND METHODS: Among 1000 kidney transplantations performed between 1980 and 2004, the coexistence of high creatinine values and urinary tract dilatation in the postoperative period, after discarding concomitant causes, was managed with a percutaneous nephrostomy. Once renal function recovered, antegrade pyelography was performed to confirm the presence and determine the location of ureteral stenosis. Ureteral dilatation was performed using a 5-French balloon-fitted angioplasty catheter. RESULTS: Fifty-six patients were diagnosed with ureteral stenosis during follow-up, an incidence of 5.6%. Transluminal balloon dilatation was the first therapeutic option in 45 cases, whereas surgery was performed directly on 11 patients. Disappearance of the stenosis as well as maintenance of an improved creatinine level was verified in 45% of cases (20 patients). Two patients experienced graft loss. Both a short time to diagnosis after transplantation (P = .06) and the presence of a previous acute rejection episode (P < .05) were good prognosis factors for the endourologic solution of a ureteral stricture. CONCLUSIONS: Balloon dilatation may be considered the definitive procedure for treatment of ureteral stenosis in selected cases. Percutaneous nephrostomy should be used for initial diagnosis and improvement in the renal function before attempting an open procedure.

Adult↗

PubMed2005

Post-renal transplantation weight gain: its causes and its consequences.

OBJECTIVE: A tendency to increased body mass index (BMI) occurs after renal transplantation. The objective of this study was to analyze the causes and consequences of this weight gain. METHODS: Two hundred twelve renal transplant recipients were divided into 3 groups according to the evolution of their BMI: BMI loss (group 1); BMI increase <10% (group 2); and BMI increase >10% (group 3). RESULTS: The mean BMI gain was 6.2%, weight gain was 3.9 kg, and BMI gain was 1.4 kg/m(2). The patients in group 3 were younger, but there were no other significant differences in gender, preoperative diabetes, acute rejection, or prior BMI. Blood pressure was similar in all 3 groups, but more group 3 patients needed antihypertensive treatment. A progressive increase in total and low-density lipoprotein (LDL)-cholesterol was also observed as patients showed increased BMI. No differences were observed regarding carbohydrate metabolism. Groups 1 and 3 showed a more unfavorable micro-inflammatory profile. The creatinine clearance level was better in group 3 compared with group 1. We found no differences regarding the number of nonfatal postoperative cardiovascular events.

Adult↗

PubMed2005

Determining factors of the response to hyperhomocysteinemia treatment in renal transplant patients.

Hyperhomocysteinemia (hyperHcy) is a risk factor for cardiovascular disease. The benefits of lowering homocysteinemia (Hcy) in renal transplant recipients through vitamin treatment are not clearly understood. The objective of this study was to establish the demographic, renal, Hcy metabolism, and microinflammation factors that determined the response to folic acid and vitamin B complex treatment in stable patients with renal transplants and hyperHcy. We studied 65 renal transplant patients with baseline hyperHcy. The mean baseline Hcy level of these patients was 22.5 micromol/L. Following treatment it fell to 14.5 micromol/L, an overall reduction of 35.5%. Forty-one patients (63%) were classified as responders; the remainder (37%), nonresponders. A bivariance analysis suggested the only significant differences between responding and nonresponding patients were the pre-treatment Hcy level and the renal function level.

Adult↗

PubMed2005

Factors involved in baseline hyperhomocysteinemia in renal transplantation.

Hyperhomocysteinemia (hyperHcy) is one cardiovascular risk. The objective of this study was to establish the prevalence demographic, and clinical and analytical factors related to hyperhomocysteinemia among renal transplant patients. The mean Hcy level was 17.3 micromol/L; the prevalence of hyperHcy was 61.2%. The population was categorized as hyperHcy and normal-homocysteinemia (Hcy) patients. Those subjects with hyperHcy were mostly men, with lower intraerythrocyte folate and vitamin B(12) levels, higher fibrinogen levels, and poorer renal function. Multivariate evaluation showed that creatinine clearance, plasma intraerythrocyte folate and vitamin B(12) levels, and plasma fibrinogen levels were independently associated with Hcy levels. Even though the Hcy level was slightly higher among patients who suffered a posttransplantation cardiovascular event, this was statistically significant.

Adult↗

PubMed2005

[Metformin in the treatment of type 2 diabetes in overweighted or obese patients].

UNLABELLED: FUNDAMENTALS AND OBJECTIVES: [corrected] Diabetes is the disease that has suffered a greater increase in his incidence in the last years. Obesity is the most important risk factor to develop this disease and metformin is considered as a first line drug in overweighted diabetic patients. The aim of this study is to evaluate the use of metformin and the degree of control of the associated cardiovascular risk factors (CVRF) in patients suffering of type 2 diabetes and overweight or obesity. PATIENTS AND METHODS: This is a transversal descriptive study over a random chosen group of 308 patients followed at primary care level. They were classified in four different groups depending on the treatment used to control them (diet, insulin, metformin and other oral antidiabetic drugs). They were evaluated upon the degree of control of the modifiable CVRF, the presence of complications and the metabolic control. RESULTS: The average age was 69.6 years, 54% of the patients female. 36.6% followed treatment with metformin and 40.5% with sulfonylureas. The macrovascular percentage of affection was 19.4%. The most frequent CVRF was arterial hypertension (76%). The goal levels of control that were less in range were the levels of cLDL < 100 mg/dl and systolic blood pressure < 130 mmHg. Diabetic patients only treated with diet had a better control of fasten glycemia and HbA1c% than those ones treated with metformin (p < 0.001). The group treated with metformin showed levels of triglycerides (TG) significantly higher than those of the diet controlled group (p = 0.009) and insulin group (p < 0.001). CONCLUSIONS: Metformin and sulfonylureas are used in a similar proportion in type 2 diabetics with overweight or obesity. There is a poor control of the majority of the CVRF in the diabetic population studied.

Aged↗

PubMed2005

[Assessment of the living renal donor. Analysis of extra-renal pathology as a limitation for donation].

The goal of the donor evaluation is to ensure the suitability, safety and well being of the donor. In order to avoid important omissions, the evaluation of potential living kidney donors should be carried according to a protocol that includes a logical sequence of complementary explorations. Old age alone is not an absolute contraindication to donation but the evaluation should be more rigorous, because increased age may be associated with more post-operative complications after nephrectomy and renal function and long term graft survival could be shorter than the ones obtained from younger living donors. A body mass index of more than 35 kg/m2 should be an absolute contraindication to renal donation. Between 30 and 35 kg/m2 the donor evaluation should be more rigorous and it should be recommended to lose weight before nephrectomy. Hypertension is one of the most common reasons to declare a potential kidney donor unsuitable. Evidence of organ damage is an absolute contraindication to kidney donation. The donation is only reasonable when hypertension is well controlled with less than two drugs. To excluded diabetes mellitus all donors should have a fasting plasma glucose measurement. Diabetes mellitus is an absolute contraindication to living donation such as an impaired glucose tolerance or impaired fasting glucose with a family history of type 2 diabetes mellitus. Another contraindication to living donation is malignant disease, and the same standards should be adopted for cadaveric donors. The exceptions are low-grade non-melanoma skin cancer and carcinoma in situ of the uterine cervix. The presence of active infection usually precludes donation. It is very important to perform a routine test for viral infections. HIV, hepatitis B and C infection of the donor are usually a contraindication to living donor. CMV donor and recipient status should be taken into account before transplantation, and the recipients at risk for CMV disease should recieve prophylactic treatment according to the transplant unit policy.

Age Factors↗

PubMed2005

[The living kidney donor: laparoscopy versus open surgery].

INTRODUCTION: Living renal donors are an important source of transplanted kidneys due to the number of patients on waiting list is progressively increasing. On the other side, they allow the pre-emptive kidney transplantation. With the aim of reducing donor obstacles such as pain, hospital stay or cosmetic results and in creasing the number of living donors, in 1995 Ratner performed the first laparoscopic nephrectomy (LLDN). By now, LLDN is a routine procedure in more than 200 centres worldwide. METHODS: Literature databases are searched. We have reviewed the data from our experience after performing 50 laparoscopic nephrectomies. RESULTS: Preoperative living donor assessment and contraindications to LLDN do not differ from the open approach. Results are very influenced by the surgeon's situation in the learnig curve. Operating times use to be longer in laparoscopic procedures. The overall complication rate and mortality of LLDN are the same for both of the approaches. Conversion to open-donor nephrectomy has been reported in 0-13% of cases (8% in our data). Postoperative pain and donor estimated blood loss are lower for LLDN, as well as the convalescence period. To avoid the possible negative effects of the laparoscopic technique on kidney graft function a lot of method's variations have been proposed for gaining access and harvesting the kidney, including the hand-assistance techniques, with the aim of minimizing operative time, pneumoperitoneus negative effect on graft function and warm ischemia time (WIT). The higher WIT is not related to delayed graft function or acute rejections when it is less than ten minutes. Delayed graft function does not differ in both approaches and creatinine values from the first month until the third year after transplantation show no differences in randomized studies. CONCLUSIONS: The laparoscopic approach to harvest the allograft from the living donor is a save and effective technique and has the advantage of being less invasive and allowing the donor a shorter convalescence. It has no negative effects on allograft function in the short term follow-up. Further studies are required to evaluate long term donor complications and allograft function and survival.

Age Factors↗

PubMed2005

[Outcomes of transplantation from living renal donor].

Living donors represent 30% of our kidneys for renal transplantation. Laparoscopic nephrectomy is the best surgical procedure to obtain them due to its clear advantages such as low morbidity, less blood supply and donor time in hospital. From March 2002 to August 2004 we performed 50 laparoscopic nephrectomies for renal transplantation. Kidneys were transplanted to recipients receiving tacrolimus 0.1 mg/kg/bid, mycophenolate mofetil 1 g/bid and prednisone 0.5-1 mg/kg/day p.o 48 hours before transplantation. Mean time for surgery was 170 minutes (120-260), warm ischaemia time 3.1 minutes (1.5-10) and cold ischaemia time 1.27 hours (0.85-4). Mean bleeding was 270 cc (100-900) and donor time in hospital 5.5 days (3-9). Four cases required conversion of the laparoscopic procedure to open surgery because of bleeding. 72 hours post-transplant mean plasmatic creatinine was 170 micromol/l. None of the patients suffered delayed graft function. 18% presented acute rejection. Survival of donor and recipient was 100% at 1 year and graft survival was 94% at 1 year (kidney losses were due to acute rejection, severe acute pancreatitis and surgical problem).

Anti-Inflammatory Agents↗

PubMed2004

[Living donor nephrectomy for kidney transplantation. Experience in the first two years].

OBJECTIVES: Laparoscopic surgery offers potential advantages in terms of diminishment of postoperative pain, shorter hospital stay, faster convalescence, and better cosmetic results. These advantages may increase kidney donation, making donation be accepted by more candidates. We report our first 2 years' experience with laparoscopic donor nephrectomy METHODS: Between March 2002 and February 2004 we performed 38 laparoscopic living donor nephrectomies for kidney transplantation. The technique of choice was the transperitoneal laparoscopic approach with four trocars, usually three of them from the start of the procedure--two 10-12 mm and one 5 mm--, and a 6.5 cm perumbilical midline incision for kidney retrieval at the end of the procedure. RESULTS: Receptor and donor survivals were 100%. Graft survival was 97.6%. There was not any case of delayed graft function. Donor: Mean operative time was 161 minutes (115-260). Mean estimated blood loss was 270 ml (100-1200). Three patients required blood transfusions, 2 units of packed red blood cells each. Mean hospital stay was 5.1 days (3-11). Mean warm ischemia time was 3.2 min. (2-10). Conversion to open surgery was necessary in four cases. Receptor: there have been three significant complications requiring surgical repair: one case of low arterial flow, one vesico ureteral leak, and one midurethra stenosis. Initial renal function: mean serum creatinine at one month was 147mmol/l, with a trend to improve to 126 mmol/l at one year, which is considered optimum. First postoperative day mean serum creatinine was 192mmol/l and the nadir was on second postoperative day with a value of 152mmol/l. CONCLUSIONS: We believe laparoscopic living donor nephrectomy is a real alternative to open surgery because it offers better recovery to the donor with the same capacity to preserve renal function in the receptor.

Humans↗

PubMed2003

Risk factors for cardiovascular disease after renal transplantation.

Cardiovascular diseases (CVD) have become the leading cause of mortality in renal transplant recipients. Well-known cardiovascular (CV) risk factors and graft dysfunction both play an important role in the development of the posttransplantation CV events. We studied 233 stable kidney transplant patients to establish the prevalence of CVD and to assess CV risk factors that can be evaluated (and modified) in daily clinical practice. While 6.2% of the patients had coronary heart disease (CHD) before the transplantation, 16% displayed at least 1 CV event posttransplantation. The most significant factors associated with CV events were as follows: gender, length of smoking, diabetes mellitus, hepatitis C virus antibodies (HCV), dyslipidemia, proteinuria, and serum creatinine levels.

Blood Pressure↗

PubMed2003

Assessment of cyclosporine therapeutic monitoring with C2 concentrations in stable renal allograft recipients.

The optimal long-term C2 target to minimize the risk of chronic allograft nephropathy (CAN) has not yet been established in a prospective study. Furthermore, it is not known whether the target is the same in patients who also receive mycophenolate mofetil (MMF). We determined the 2-hour postdose concentration (C2) in a cohort of 65 maintenance renal transplant patients. The mean C0 level was 0.12 microg/mL and the C2 was 0.62 microg/mL. The overexposed patients are 14%. There was a good correlation between C0 and C2, and between C2 and the cyclosporine (CsA) dose. Patients receiving MMF display lower levels of C0 and C2, lower dosages of CsA, and higher levels of plasma creatinines. We did not observe significant differences on relating the level of absorption to patient age and sex, creatinine level, CsA dose, or coadministration of MMF. In conclusion, there is a low incidence of overexposed patients. C2 levels of approximately 0.6 microg/mL (and possibly may be sufficient in renal transplant patients. somewhat lower [0.5 microg/mL] in patients receiving MMF) Patients who display slow or fast absorption of CsA do not have any apparent characteristic.

Adult↗

PubMed2003

Tacrolimus in induction immunosuppressive treatment in renal transplantation: comparison with cyclosporine.

The aim of the study was to compare the efficacy and safety of induction immunosuppression therapies based on tacrolimus or cyclosporine (CsA) in kidney transplantation. The 240 kidney allograft recipients were divided into two groups: group 1 (n=94) received tacrolimus (.01 mg/kg per day), mycophenolate mofetil (MMF, 2 g/d), and steroids (30 mg/d); and group 2 (n=146) CsA (6 mg/kg per day), MMF (2 g/d), and steroids (30 mg/d). Antilymphocyte serum was administered in cases of acute tubular necrosis. The acute rejection rate was higher among group 2 (30.6%) compared with group 1 patients (12.2%) (P=.001). There were no significant differences between the groups in terms of age, gender, body surface area, serologic virus markers (in donor and recipient), baseline creatinine levels, cause of death, HLA incompatibilities, response to acute tubular necrosis, and number of dialysis sessions. We conclude that both immunosuppressive regimens are effective and safe in kidney transplantation. The survival rates of patients and grafts were similar, but the incidence and degree of acute rejection events were reduced in group 1; this finding may forecast a decreased incidence of chronic renal allograft nephropathy.

Adrenal Cortex Hormones↗

PubMed2003

Significance of cytomegalovirus infection in renal transplantation.

The aim of this study was to establish the relationship between vascular lesion chronic allograft nephropathy (CAN) and the presence of cytomegalovirus (CMV) in kidney transplanted patients. We studied 259 consecutive kidney transplant recipients with a minimum follow-up of 6 months; the induction immunosuppressive therapy included a calcineurin inhibitor, mycophenolate mofetil, steroids, and the use of an antilymphocyte serum if the patients developed delayed graft function. CMV early antigen detection (pp65) was performed on a weekly basis between days 30 and 90 post transplantation. Prophylactic treatment was administered in the donor +/recipient-risk group, and preemptive therapy delivered for positive antigenemia namely 3 days of intravenous [IV] gancyclovir [GCV] plus 11 days of oral therapy [in the case of infection], or 14 days of IV GCV [in the case of disease]). An acute kidney allograft rejection episode preceded CMV in 64.3% of the patients, and CMV preceded acute rejection in 35.7% of the cases. We conclude that CMV disease is an independent risk factor for CAN. CMV infection is probably associated with CAN, suggesting that the greater the viral load, the higher the risk of CAN. It may be advisable to perform universal prophylaxis to lower the viral load and CAN.

Cytomegalovirus Infections↗