Riassunto analitico
BACKGROUND - Renal biopsy continues to be a pivotal tool in the diagnosis and management of renal diseases. Ultrasound guidance and automated needles have improved safety and sample adequacy, yet some contraindications to percutaneous biopsy still exist. Other techniques have been developed for high-risk patients including laparoscopic and transjugular renal biopsy. The aim of this study is to evaluate the safety and efficacy of such techniques based on our center’s experience.
MATERIALS AND METHODS - We retrospectively examined diagnostic yield and complication rates in patients with native kidney disease and contraindications to percutaneous renal biopsy (PRB) who underwent either laparoscopic (LSRB) or transjugular renal biopsy (TJRB) at our center over the last seven years. LSRBs were carried out either with a conventional, retroperitoneoscopic approach or with the newer laparoendoscopic single-site (LESS) technique.
RESULTS - Between August 2008 and May 2015 26 patients underwent LSRB while 12 patients underwent 13 TJRB procedures, with technical success in 25/26 cases (96 %) and 12/13 cases (92 %), respectively. The mean numbers of glomeruli obtained in successful biopsies were 51.7±24.7 with LSRB and 7.8±4.6 with TJRB, providing adequate samples for histopathological diagnosis in 25/25 (100%) and 10/12 cases (83%). The difference in tissue yield was statistically significant (Student’s t-test, p<0,001). Patients had one or more contraindications to PRB including solitary kidney (13/26), uncontrolled hypertension (5/26) and obesity (3/26) in the LSRB group, or underlying liver disease (11/12), thrombocytopenia (10/12) and uncontrolled hypertension (3/12) in the TJRB group. The laparoscopic approach was also indicated to perform ureterolithotomy in a patient with concomitant urolithiasis, while the transjugular route was chosen in order to perform combined liver and kidney biopsy in 10/12 cases, with success in nine. There was no significant difference in the mean preprocedural serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) between two groups, whereas the mean preprocedural hemoglobin (Hb, 12.1±1.6 versus 10.3±1.3), platelet count (236.7±62.7 versus 88.1±92.8) and International Normalized Ratio (INR, 1.02±0.08 versus 1.57±0.48) did differ significantly between the LSRB group and the TJRB group (Student’s t-test, p≤0,001). Major complications requiring blood transfusions occurred in two LSRB cases (7.7 %) and one TJRB case (7.1%), with no significant difference in either major or total complication rates (Pearson’s Chi-Square test).
DISCUSSION - Our results indicate that the patient groups exhibited similar clinical features, except for stronger risk factors for bleeding in the group who underwent TJRB, or solitary kidney and obesity in those who underwent LSRB. The difference in complication rates was not statistically significant, although LSRB allows a diagnostic yield (in terms of sample adequacy) superior to TJRB.
CONCLUSION – The use of TJRB and LSRB allows to overcome most of the common contraindications to renal biopsy. LSRB ensures an excellent level of sample adequacy; TJRB, however, showed to be safe in patients with high risk of bleeding, not eligible for a surgical approach. We have suggested a flow-chart to help in the choice of the most appropriate approach for each patient, with the aim of maximizing diagnostic possibilities and minimizing adverse events. Further studies on larger groups, and possibly cost-effectiveness analyses are needed to assess which technique is indeed preferable, e.g. when indications overlap.
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