Indications, immediate complications and tissue adequacy of ultrasound guided percutaneous renal biopsy at Moi Teaching and Referral Hospital- Eldoret Kenya

Abstract

Background: Ultrasound-guided percutaneous renal biopsy (USG PRB) is a minimally invasive procedure involving real-time ultrasonographic guidance, a spring-loaded biopsy gun, and with or without a coaxial needle. However, a wide range of complications has been reported, such as arteriovenous fistulas, small perirenal hematomas, large actively bleeding perirenal hematomas, which might require intervention like blood transfusion, embolization and nephrectomy. In some cases, death was reported. Objective: To assess the indications, immediate complications and tissue adequacy of Ultrasound-guided percutaneous renal biopsy at Moi Teaching and Referral Hospital- Eldoret Kenya. Methods: This was a census, a prospective descriptive study conducted among 48 adult patients scheduled for USG PRB from November 2019 to October 2020. A data collection form was utilized to record age, gender, pre-biopsy laboratory findings, renal biopsy indications, post-biopsy complication findings and tissue adequacy. Biopsies were taken by the consultant radiologist under ultrasound guidance using a 3.5-5MHZ curvilinear transducer of Mindray M7 (ultrasound machine with exquisite Doppler and greyscale capability), coaxial needle and biopsy gun. A two to five core tissues were obtained. Biopsy tissues were considered adequate if they contained at least eight glomeruli for native kidneys. One core tissue length more than 10mm for renal masses and a histopathologist can make a diagnosis. Continuous variables were summarized using means and standard deviations. Categorical variables were summarized in frequency, percentages and bar graphs. Fisher's exact test was done to assess the relationship between complications and associated factors. A p-value of less than 0.05 considered significant. Results: The mean age was 34.8 years (SD=13.1). The majority of the participants (52.1%) were females. Nephrotic syndrome was the commonest indication for renal biopsy (45.8%) followed by renal masses (25.0%), SLE (20.8%) and nephritic syndrome (8.3%). The overall complications were 8(16.7%). Seven patients (14.6%) developed minor complications, namely, macrohematuria (n=5) and perirenal hematoma less than 5cm (n=2). One participant (2%) developed a major complication (perirenal hematoma >5 cm and hypotension) where transfusion and gelfoam embolization was done. The number of biopsy passes had a statistically significant association with the complications (p-value < 0.001). However, gender, creatinine and indications for PRB were not associated with complications. The majority of the participants (95.8%) whose tissue specimens were obtained were declared adequate by the histopathologist. Conclusions: Nephrotic syndrome was the most common indication for Ultrasoundguided PRB. Macrohematuria was the commonest complication of USG PRB. More than four biopsy passes were significantly associated with post PRB complications. Up to 95% of the biopsy tissues were adequate. Recommendations: Close monitoring for patients done more than 4 biopsy passes is recommended After USG PRB.