Feasibility and Safety of Percutaneous Kidney Biopsy in Small Kidneys: Breaking the Paradigm.

INTRODUCTION: The percutaneous kidney biopsy (PKB) is an essential tool in nephrology; small kidney size has been a relative contraindication to PKB and there is limited data on the safety and utility of performing PKB in this setting. Our aim was to describe the complications of PKB in small kidneys and to assess if kidney biopsy results have an impact on medical decisions and outcomes. METHODS: This was a retrospective, descriptive, and observational study. Patients older than 16 years of age with a decreased kidney size (≤8 cm) and undergoing PKB of native kidneys from July 2019 to December 2022 were included. RESULTS: Twenty-five patients were included, 19 women and 6 men. The mean age was 42.3 ± 18.04. The mean kidney length was 7.56 ± 0.33 and the mean width was 4.2 cm. All patients received only 1 puncture, obtaining an average of 12 glomeruli. The mean blood urea nitrogen and serum creatinine were 36 mg/dL and 1.94 mg/dL, respectively and the mean Hgb (hemoglobin) was 12.87 ± 2.81 g/dL. Minor complications occurred in 5 patients, perirenal hematoma in 3 patients, hematuria in 1 patient, and hematoma plus hematuria in 1 patient. Histological examination showed FSGS, lupus nephritis, other Glomerular disease, crescentic glomerulonephritis, and tubulointerstitial nephritis in 36%, 20%, 16%, 16%, and 12% of the cases, respectively. Biopsy resulted in management modification in 64% of cases. In a bivariate analysis, kidney size was not associated with higher complication rates. CONCLUSIONS: PKB in small kidneys is a feasible and safe procedure when properly planned, providing an adequate sample in all cases, with an insignificant number of minor complications, and that is clinically relevant.

Kidney biopsy during pregnancy: a difficult decision. A case series reporting on 20 patients from Mexico.

BACKGROUND: Kidney biopsy is a routine procedure in the diagnosis of kidney disease, but during pregnancy it carries potential adverse effects for both mother and child, aside from the challenges of obtaining adequate tissue samples. Nevertheless, a precise diagnosis is necessary when specific and potentially toxic treatments are to be used during pregnancy. The present report presents our experience with regard to the usefulness and safety of kidney biopsies during pregnancy. METHODS: Retrospective analysis of clinical indications, complications, histopathological diagnoses, and treatment of patients who had kidney biopsies done at a single academic center during gestation weeks 11-30 between January 2015 and January 2019. RESULTS: Kidney biopsies were carried out in 20 pregnant patients with nephrotic proteinuria. Biopsy was adequate in all patients. The histological diagnoses included focal segmental glomerulosclerosis (collapsing, tip and perihiliar varieties), membranous lupus nephropathy, diabetic nephropathy, and IgA nephropathy. Treatment was associated with reduction of proteinuria in 17 patients and reduction of serum creatinine in 9 out of 11 patients who had serum creatinine ≥ 1 mg/dl at the time of biopsy. There was one major bleeding complication that required transfusion of one unit of blood. There was a high incidence of preeclampsia, preterm delivery, and low birth weight despite appropriate kidney disease therapy. CONCLUSIONS: Kidney biopsy may be done during pregnancy when therapeutic decisions depend on a precise pathologic diagnosis.

[Prevalence, risk factors and consecuences of late nephrology referral]. / Prevalencia, factores de riesgo y consecuencias de la referencia tardía al nefrólogo.

BACKGROUND: Late referral of patients with chronic kidney disease (CKD) to specialized care by the nephrologist is associated with worse patient outcomes while on dialysis. OBJECTIVES: To determine the prevalence, risk factors, and consequences of late nephrology referral at a Mexican tertiary care hospital. MATERIAL AND METHODS: Retrospective chart review of all adult patients who began chronic hemodialysis between 2002 and 2006 at the National Institute of Cardiology "Ignacio Chavez" (NICICh), Mexico City. Timing of referral to Nephrology Department was classified as early, late or very late if the time elapsed between referral and initiation of dialysis was < 1 month, between 1-6 months or > or = 6 months, respectively. Socio-demographic, clinical, laboratory and echocardiographic characteristics were compared according to timing of referral. RESULTS: Eighty four out of 150 patients were included in the analysis. Of these, 56% were referred < 1 month, and an additional 15% between 1-6 months prior to the initiation of chronic hemodialysis. In univariate analysis, being referred by a relative or friend was associated with a higher risk (p = 0.04), and being employed with a lower risk of late referral (p = 0.05). Late referred patients were more likely to require emergency dialysis and hospitalization, and of not having a permanent vascular access for their first dialysis. They also had a higher prevalence of severe anemia (hematocrit < 28%) and of residual kidney function (estimated glomerular filtration rate < 5 mL/min/1.73 m2), as well as increased left ventricular mass. CONCLUSIONS: Late nephrology referral is highly prevalent in our population and is associated with markers of suboptimal predialysis care at the onset of chronic dialysis.