Incidence and Risk Factors for Hemorrhagic Complications after Percutaneous Renal Biopsy using a 16-Gauge Needle Followed by 6 Hours of Bed Rest

Background: The procedures and management protocols for percutaneous renal biopsy (PRB) are different among institutions. Here we present the outcomes of our protocol and identify risk factors for hemorrhagic complications (HCs). Methods: From 2007 through 2016, 175 patients received PRB using a 16-gauge biopsy needle with real-time ultrasound guidance. In a single session, three specimen cores were obtained. Post operatively, all patients were monitored with strict bed rest without sandbag compression for six hours. Adverse events were graded according to the Clavien-Dindo classification. Results: Ninety-seven patients (55.4%) were female and the median age was 48.0 years (IQR 37.0-64.0). The median estimated glomerular filtration rate based on serum creatinine (eGFRcreat) was 57.8 mL/min/1.73 m2 (IQR 28.1-87.8). The median number of glomeruli assessable in each specimen was 19 (IQR 12-29). Symptomatic HCs developed in 9 patients (5.1%). All the events occurred within 6 hours after PRB. Selective transcatheter arterial embolization and blood transfusion were required in 1 and 7 patients, respectively, but there was no grade IIIb to V event. In univariate analysis, predictive factors for symptomatic HCs were being female (OR 1.102, p = 0.006), a platelet count < 15.0 x 104/μl (OR 7.405, p = 0.004) and eGFRcreat < 30 mL/min/1.73 m2 (OR 6.300, p = 0.005). Conclusion: PRB using a 16-gauge needle followed by 6 hours of strict bed rest secures sufficient samples for histological diagnosis with a low incidence of severe HCs. Furthermore, monitoring with six hours of bed rest contributes to early detection and management of severe HCs. Citation:Maehana T, Miyamoto S, Ichihara K, Tanaka T, Masumori N. Incidence and Risk Factors for Hemorrhagic Complications after Percutaneous Renal Biopsy using a 16-Gauge Needle Followed by 6 Hours of Bed Rest. J Urol Nephrol. 2017;4(1): 5. J Urol Nephrol 4(1): 5 (2017) Page 02 ISSN: 2380-0585 All patients were hospitalized and PRB was performed by urologic residents under the supervision of attending urologists. Anti platelet and anticoagulant drugs were discontinued before biopsy according to the institutional requirement and, in some cases, continuous intravenous heparinization was performed until 6 hours prior to PRB. The PRB procedure was performed as follows. First, the patient was placed in the prone position. Then the bilateral kidneys were checked by ultrasound (Hawk 2102 EXL; B-K Medical, Denmark). A kidney with easy visualization was selected as the target of PRB and the puncture site to access the lower pole was determined. Next, the puncture site was anesthetized with using local anesthesia with 1% xylocaine after disinfection of the skin with 10% povidone iodine and a 5-mm skin incision was made there. PRB was performed using a 16-gauge automated biopsy needle (ACECUT®, 16G × 115 mm, TSK LABORATORY, Japan). The puncture was done three times or more to obtain three sufficient cores of renal tissue. After the procedure, the puncture site was compressed manually for several minutes to control active bleeding from the incision, and then the patient was placed in the supine position. Care protocol after PRB Strict bed rest in the supine position without sandbag compression was required for 6 hours. Routine in dwelling bladder catheterization and administration of a hemostatic agent were not performed. Vital signs were checked at the time just after the biopsy, 1 and 6 hours later, and when patients complained any kind of symptoms. After 6 hours passed, patients without symptoms were allowed to turn over, elevate the head of the bed, and could walk for urination or defecation. The next morning (after about 18-20 hours), patients were free from restrictions except for heavy exercise and lifting of heavy weights if there were no problems with blood tests and vital signs. Routine ultrasound and computed tomography were not performed after PRB. Anti platelet and anticoagulant drugs were resumed after 2 or 3 days. Definition of complications Medical charts of enrolled patients were retrospectively reviewed, and all adverse events within 30 days after PRB were investigated. The severity of adverse events was graded according to the Clavien-Dindo (CD) classification [8]. In this system, any deviation from a normal postoperative course without the need for intervention was classified as Grade I. Therefore, events/symptoms that required extended bed rest for over 6 hours were defined as Grade I. In addition, any situation requiring blood transfusion, so-called hemorrhagic complications, was classified as Grade II. Grade III was for those requiring surgical, endoscopic or radiological intervention and IIIa was not under general anesthesia. In the present study, the onset time of a hemorrhagic complication was defined as the time when the patient showed the following symptoms or signs: gross hematuria, severe back pain, nausea or vomiting, hypotension, and tachycardia. Compliance with Ethical Standards