Biomedical subjects

R Marcen Letosa

Publications and source records attributed to R Marcen Letosa.

11 recordsLinked to original sources

PubMed1997

[Neoplasm prevalence in renal transplantation].

OBJECTIVE: To analyze the prevalence of neoplasms in renal transplant patients and the relative risk for each tumor type according to the immunosuppression regimen. METHODS: 609 renal transplants were reviewed. The risk index was determined by the ratio of the cases observed and predicted. RESULTS: Tumor prevalence was 4.9% (30/609); 6.3% (25/393) were males and 2.3% (5/216) were females. The most common tumors were cutaneous tumors other than melanoma, accounting for 2.4% (15/609), followed by Kaposi's sarcoma, pulmonary epidermoid carcinoma and genitourinary tumors (0.5%) and non-Hodgkin lymphoma (0.3%). Tumor prevalence was 6.8% for the group treated with azathioprine-prednisone and 3.9% for the cyclosporine A-prednisone-treated group. The estimated relative risk of having a neoplasm was 10-fold higher for the males and 4.2-fold higher for the females vs the general population. The mortality rate was 36.6%; specifically tumor-related in 82%. The mortality rate for those with solid tumors was 77.7%. The long-term survival rate for the group that developed a tumor was significantly lower than that of the general population, 75% vs 53%, respectively (p < 0.05). CONCLUSION: In this series no significant differences were observed relative to tumor prevalence or type according to the immunosuppression regimen. A recipient of a renal graft has a higher risk of developing a tumor. Cutaneous tumors were the most frequent. The long-term survival is lower for recipients of renal grafts who develop a tumor.

Adult↗

PubMed1995

[Assessment of arterial hypertension associated with renal transplantation using Doppler ultrasonography].

OBJECTIVES: The incidence of arterial hypertension post-renal transplantation has been reported to be 48.6%. The present study investigated the usefulness of echo Doppler in detecting renal artery stenosis and the effects of arterial pressure control and hypotensive agents on the vascular resistance of the renal graft. METHODS: A total of 234 echo Doppler studies were done in 110 patients. The pulsatility index (PI), resistance index (RI), acceleration and mean velocity (MV), maximum systolic (SVMX) and minimum diastolic (DVMN) velocities of the external iliac, renal, segmental, interlobar and arcuate arteries were determined. RESULTS: In the stenotic segment, an elevation of SVMX was observed, followed by turbulent flow in the post-stenotic segment in 73% of the cases with arterial stenosis. The hypertensive patients had a higher external iliac artery RI than the normotensives. The beta-blockers reduced the RI in large vessels (external iliac), the vasodilators in medium-sized extraparenchymal vessels (segmental) and the calcium antagonists changed the PI in the smaller caliber intraparenchymal vessels (interlobar and arcuate). CONCLUSIONS: Evaluation by echo Doppler is the first diagnostic approach in patients suspected as having arterial stenosis of the renal graft. It permits evaluating blood flow changes from hypertension and hypotensive agents.

Adult↗

PubMed1994

[Nephrectomy of the transplanted kidney].

A total of 118 allograft nephrectomies (TX) were performed after 474 renal transplants (TR) (24.9%). 49.1% of the patients were immunosuppressed with azathioprine-prednisone (AZA-PRED) and 50.9% with cyclosporine-prednisone (CSA-PRED). Mean time to TX after returning to hemodialysis was 36.2 +/- 6.4 days (0-372). Acute rejection (33.1%) was the first cause of TX, followed by chronic rejection (26.3%), vascular complications (25.5%), recurrent renal disease (5.9%), non-functioning allograft (4.2%) and not clearly established cause (1.7%). The surgical technique was extracapsular in 70.3% of the cases and subcapsular in 29.7%. The mean post-TR time to TX was significantly greater (p < 0.01) for the subcapsular technique. The mean surgical time was 106 +/- 4.4 min (45-300). Post-TX morbidity was 34%. Hemorrhage (11.2%) was the most frequent complication. The rest of the complications were infection (10.4%), neurologic (5.4%), gastrointestinal (4.5%), pulmonary (3.6%), cardiovascular (2.7%), nerve lesions (2.7%), lymphocele (0.9%) and urinary fistula (0.9%). The post-TX mortality was 6.5% (7/118), although it was significantly lower in the patients immunosuppressed with CSA-PRED (1.6%) than in those treated with AZA-PRED (10.3%).

Adolescent↗

PubMed1978