PubMed Health⌕ Search

Biomedical subjects

M J Castro

Publications and source records attributed to M J Castro.

66 records · Page 4Linked to original sources
PubMedDate not supplied

Postnephrectomy arteriovenous fistula.

The development of the postnephrectomy arteriovenous fistula (PNAVF) between the renal vessels stumps is rare. Here we present a case report of PNAVF, and review the diagnosis, treatment and prevention. The most common clinical features include a loud murmur over the previous nephrectomy scar, and heart failure resistant to common medical treatment. A 58-year-old white woman was admitted to the hospital for a complete evaluation of an unexplained congestive heart failure with no response to common medical treatment. She had had a right nephrectomy for pyonephrosis 13 years before. The diagnosis of PNAVF was suspected because over the right lumbar region a definite trill was palpated, and on auscultation a harsh, machinery-like murmur was heard. The diagnosis was confirmed by aortogram and selective renal arteriography. In May 1989, the right arteriovenous was excised through a right subcostal transperitoneal approach. The renal vessel stumps were individually ligated and sutured separately close to aorta and vena cava. The patient's postoperative course was entirely uneventful in the following seven years. We conclude that during nephrectomy, the renal vessels should be ligated separately, and the transfixation in mass of the stumps avoided to prevent arteriovenous fistula.

Arteriovenous Fistula↗
PubMedDate not supplied

Anatomical study of the renal veins observed during 342 living-donor nephrectomies.

The anatomical variations of renal veins observed during 342 nephrectomies in living donors are described, 311 cases on the left side and 31 on the right. The following anatomy of the renocava veins was observed: 1. On the left side the renal vein was always unique (311/311) and had two tributaries (suprarenal and gonadal veins) in 100 per cent and one or more renolumbar veins in 65.27 per cent, encircling the aorta in 1.07 per cent, was retroaortic in 1.4 per cent; and the inferior vena cava was double in 0.64 per cent; B- on the right side the renal vein was double in 29 per cent (9/31) and had only one tributary (gonadal vein) in one case, for 3.22 per cent (1/31); three or more renal veins in 9.7 per cent (3/31). We concluded that the left renal vein is always unique, presenting variations principally in its tributaries and trajectory. On the right side, the renal vein was double or triple in 38.79 per cent.

Adult↗
PubMedDate not supplied

Risk factors responsible for ultrafiltration failure in early stages of peritoneal dialysis.

OBJECTIVE: To define risk factors for ultrafiltration failure (UFF) during early stages of peritoneal dialysis (PD). DESIGN: Retrospective analysis of a group of patients whose peritoneal function was prospectively followed. SETTING: A tertiary-care public university hospital. PATIENTS: Nineteen of 90 long-term PD patients required a peritoneal resting period to recover UF capacity: 8 had this requirement before the third year on PD (early, EUFF group) and 11 had a late requirement (LUFF group). The remaining 71 patients, those with stable peritoneal function over time, constituted the control group. MAIN OUTCOME MEASURES: Peritoneal UF capacity under standard conditions (monthly) and small solute peritoneal transport (yearly). RESULTS: None of the conditions appearing at the start of PD or during the observation period could be definitely identified as the cause of UFF. There were no differences in characteristics between the EUFF group and the other two groups, except for the higher prevalence of diabetes in the EUFF group. Residual renal function (RRF) declined in all three groups during the first 2 years, with rapid loss during the third year in the EUFF group. This rapid loss in RRF was coincident with UFF. Peritoneal solute and water transport at baseline was similar in the three groups. After 2 years on PD, individuals in the EUFF group showed a significantly lower UF and higher creatinine mass transfer coefficient values than those in the LUFF group. Diabetic patients in the control group showed remarkable stability in UF capacity over time. During the second year on PD, requirement for increases in dialysate glucose concentration was 3.4 +/- 0.5% in the LUFF group, but as high as 25.5 +/- 24.2% in the EUFF group. The accumulated days of active peritonitis (APID, days with cloudy effluent) were similar for the three groups after 1, 2, and 3 years on PD. Interestingly, diabetic patients in the control group showed an APID index significantly lower than the overall EUFF group. Diabetics in the control group also had significantly lower APID versus nondiabetics in the control group (p = 0.016). CONCLUSIONS: Our findings suggest that certain patients develop early UFF type I. Diabetic state and a higher glucose requirement to obtain adequate UF suggest that glucose on both sides of the peritoneal membrane could be responsible. The mechanisms for this higher requirement remain to be elucidated. The identification of a larger cohort of these early UFF patients should lead to a better exploration of the primary pathogenic mechanisms.

Hemodiafiltration↗
PubMedDate not supplied

Vascular endothelial growth factor (VEGF) levels in peritoneal dialysis effluent.

BACKGROUND: Long-term peritoneal dialysis (PD) patients who develop peritoneal ultrafiltration failure have an abnormally large number of capillaries and sclerotic changes in peritoneal biopsy. Peritoneal vascular endothelial growth factor (VEGF) production has been suggested to explain the higher levels in peritoneal effluent than in plasma. The high effluent VEGF levels have been related to peritoneal changes consisting of increased permeability to small molecules. To further analyze the relationship between peritoneal neoangiogenesis induced by VEGF and peritoneal transport, we studied peritoneal effluent VEGF levels in active PD patients. METHODS: VEGF levels were determined in serum and plasma, and in peritoneal effluent (PE) after 4, 8 and 15 h dwell times. RESULTS: PE VEGF levels were 58.6+/-33.7 pg/mL, with a mean VEGF D/P ratio of 0.45+/-0.29 (range 0.06-0.93). In low-transport patients (n = 7) this ratio did not differ from high-average ones (n=5) (0.48+/-0.3 and 0.41+/-0.1, NS). In multivariate analysis, the VEGF D/P ratio showed no correlation with the independent variables included in this study. VEGF levels were higher in 15 h than in 8 h effluent; so the VEGF D/P ratios were higher as well. Regression analysis showed a direct correlation between PEVEGF levels and dwell time (r: 0.57, p = 0.03), but not between VEGF D/P ratio and dwell time. PEVEGF levels directly correlated with effluent protein content. Regression analysis showed no correlation between PEVEGF levels and age, time on PD, days of peritonitis, urea and creatinine-mass transfer coefficients, ultrafiltration capacity, and accumulated glucose dose. Multivariate regression analysis showed correlation only between PEVEGF levels and dwell time, but not with the other independent variables. CONCLUSIONS: This study confirms that VEGF is present in fresh PE from PD patients at levels that suggest local production and filtration from plasma. Peritoneal effluent VEGF levels are not significantly associated with peritoneal functional parameters and background, and seem to be influenced by ultrafiltration in a dilution process. We believe that the role of VEGF in peritoneal pathophysiology is part of a complex relationship involving multiple peritoneal structures and other growth factors, including local counteracting factors for VEGF that regulate neoangiogenesis.

Dialysis Solutions↗
PubMedDate not supplied

Diverticular disease and treatment with gastric acid inhibitors do not predispose to peritonitis of enteric origin in peritoneal dialysis patients.

OBJECTIVE: Enteric peritonitis (EP) is an infrequent complication of peritoneal dialysis (PD), with severe consequences for peritoneal membrane viability and patient outcome. Factors such as diverticular disease and gastric acid inhibitors have been implicated in its appearance. We investigated several risk factors, including those mentioned below, that can influence the development of EP. DESIGN: Retrospective cross-sectional study. SETTING: Tertiary-care public university hospital. PATIENTS: Fifty-seven PD patients treated in our PD unit during August 1998. MAIN OUTCOME MEASURES: A barium enema was performed on 50 of the 57 patients (the remaining 7 patients refused it) in order to exclude the presence of diverticulosis. All episodes of peritonitis occurring in those patients, including EP, were registered. Enteric peritonitis was defined as that caused by gram-positive, gram-negative, or fungus micro-organisms that colonized the intestinal tract, excluding episodes secondary to genitourinary tract or peritoneal catheter exit-site infections. RESULTS: Twenty-four patients showed diverticular disease in the barium enema, but only 5 of them (21%) had any EP episode. Five of the 26 patients with no diverticula (19%) had EP. Fifty-five episodes of peritonitis were reported in 21 patients; 15 episodes of EP (27.3% of all) developed in 11 patients. Seven of the 11 patients (64%) required peritoneal catheter removal and 3 of them (27%) finally were transferred to hemodialysis due to consequences of the EP episode. Logistic regression analysis did not find any of the independent variables analyzed (age, sex, time on PD, type of PD, peritoneal transport parameters, presence of polycystic kidney disease, constipation or diverticulosis, or treatment with gastric acid inhibitors, or phosphate-binding agents) to be risk factors for developing EP. CONCLUSIONS: Neither diverticulosis nor treatment with gastric acid inhibitors seem to be risk factors for developing peritonitis of enteric origin in PD patients. This type of peritonitis has to be promptly identified and treated in order to diminish the high frequency of peritoneal catheter removal and PD dropout due to such episodes.

Adolescent↗
PubMedDate not supplied

[Chylothorax. An infrequent complication in surgical exeresis of the esophagus].

We report a case of massive bilateral chylothorax occurring after surgical resection of the esophagus in a patient with esophageal neoplasm. The surgical approach consisted of a thoracotomy and a cervicostomy. The relevance of this case is based on the low incidence of chylothorax after esophageal surgery. The literature indicates an incidence of about 0.9 to 3%. In our series of 200 patients operated on during the last 10 years we found and incidence of 2%. The patient herein reported presented an immediate postoperative clinical picture of respiratory insufficiency associated with the presence of milky fluid in the pleural drainage. Hematologic and biochemical examination of the pleural fluid confirmed the diagnosis of chylothorax. During the first 24 hours we collected a total volume of 2,500 ml of chyle. The patient was treated with conservative procedures including parenteral nutrition and intravenous reposition of fluids. After 48 hours the total volume of chyle reached 8,500 ml and the patient died.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

[Factors involved in bacterial translocation in an experimental model of intestinal obstruction].

We designed a model of intestinal obstruction (IO) to study the histological alterations in the intestinal wall and the mesenteric lymph nodes (MLN). Therefore we used 32 Sprague-Dawley rats and under anesthesia a laparotomy was performed and the distal ileum was ligated with 3-0 silk, producing a complete occlusion. At different interval (24, 48, 72 and 96 hours) the animals were sacrificed by cervical dislocation and were histologically analyzed. At 24 hours post IO, congestion, edema and a inflammatory infiltrate were observed at the level of the lamina propia and the MLN were reactive. At 48 hours the congestion and edema increased and the intestinal mucosa began to fragment, allowing the bacteria to translocate and getting to the lymph nodes in the intestinal wall. The reactivity at the MLN increased. The observation of bacterial translocation in IO widen the scope of the alterations in this pathology, were not only absorption of toxic products and endotoxin occurs in the compromise segment and this phenomenon could explain the incidence of bacteremia and sepsis in the IO patients.

Animals↗
PubMedDate not supplied

Erythropoietin treatment decreases cardiovascular morbidity and mortality in CAPD patients.

OBJECTIVE: To analyze the effects of recombinant human erythropoietin (rHuEPO) therapy on cardiovascular (CV) morbidity and mortality among continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Retrospective comparative study. SETTING: CAPD unit in a university hospital. PATIENTS: Forty-two patients on rHuEPO treatment for at least one year were compared with an rHuEPO nonuser group of 113 patients. Subcutaneous rHuEPO doses were adjusted to a hemoglobin objective level of 10.5-13.5 g/dL. Fifty-seven patients were considered as high cardiovascular risk (HCVR), 17 in the rHuEPO group and 40 in the rHuEPO nonuser group. Ninety-eight patients were classified as low cardiovascular risk (LCVR), 25 of whom were in the rHuEPO group. RESULTS: The incidence of cardiovascular morbidity was more frequent in the rHuEPO nonuser than in the rHuEPO user group (40% vs 22%) and in HCVR than in LCVR patients (59.6% vs 20.4%). By multiple logistic regression analysis, the best model to explain the development of cardiovascular morbidity comprises rHuEPO treatment, CV risk, and age. In the rHuEPO user group, HCVR and LCVR patients did not show significant differences in survival, while in the rHuEPO nonuser group, HCVR patients had a lower survival rate than LCVR patients (p = 0.0003). Cox proportional hazards model revealed that LCVR patients had an excellent prognosis compared with HCVR patients in the rHuEPO nonuser group, but this difference disappeared in the rHuEPO user group. CONCLUSION: These data show a beneficial effect of rHuEPO treatment on cardiovascular morbidity and mortality in CAPD patients, evidenced by the elimination of the correlation between prior cardiovascular risk and subsequent mortality.

Adult↗