Low incidence of adverse events in outpatient pediatric renal allograft biopsies

Abstract

In 1999, our center implemented a policy of outpatient protocol biopsies as standard practice for the clinical management of pediatric renal allograft recipients. In order to determine the safety of this procedure, we conducted a retrospective chart audit of all outpatient renal allograft biopsies performed at our center. Biopsies were performed under conscious (midazolam) or procedural (propofol/fentanyl) sedation. Localization of the lower pole of the renal allograft was achieved with renal ultrasound. Using a Biopty gun with a 16-gauge needle, two cores were obtained. Patients were discharged four h post-biopsy. Patient demographics, hospital length of stay (LOS), specimen adequacy (per Banff criteria) and major and minor adverse events were recorded in a central database. Data were expressed as mean +/- SD. From June 1999 to July 2004, we performed 162 biopsies in 43 pediatric renal allograft recipients. Most patients underwent extraperitoneal transplantation (42/43, 97.7%) and were greater than five yr of age at biopsy (129/131 biopsies, 98.5%). The majority of these procedures (131/162, 80.9%) were conducted in the outpatient department, with 113 of 131 (86.3%) being obtained for protocol (n = 89) and one-month follow-up acute rejection therapy (n = 24) indications. Patients underwent 3.7 +/- 2.7 biopsies (range = 1-11). Specimen adequacy was achieved in 119 of 124 (96.0%) of documented cases. The overall incidence of adverse events was 12 of 131 (9.2%) biopsies, all of which were minor in severity. Macroscopic hematuria was the most common minor adverse event, occurring after 11 of 131 (8.4%) biopsies. While macroscopic hematuria prolonged LOS (adverse events vs. no adverse events: 23.0 +/- 26.0 vs. 8.6 +/- 4.1 h, p = 0), none of these episodes required major surgical or radiographic interventions. We conclude that in patients greater than five yr of age with extraperitoneal renal allografts, outpatient protocol biopsies using a 16-gauge needle are sufficiently safe to justify their inclusion in the routine clinical management of pediatric renal allograft recipients and in pediatric clinical trials.

Renal Biopsy in the Pediatric Patient

“…Similar findings in native renal biopsies were also reported from a large Brazilian cohort (Piotto et al, 2008). As such, Birk et al (Birk et al, 2007) hypothesized that the slightly higher incidence of post-biopsy gross hematuria (8.4%) in their cohort of 43 renal transplant recipients compared to previously published reports (1.9-3.5%) was their use of a larger 16-G needle compared to an 18-G needle used elsewhere. With regards to other factors, several retrospective analyses have shown no significant difference in complication rates whether the biopsy was performed as an outpatient or inpatient procedure (Hussain et al, 2003(Hussain et al, , 2010Simckes et al, 2000), under general anesthesia or sedation (Durkan et al, 2006;Hussain et al, 2010;Webb et al, 1994), by a supervised trainee or by an attending physician or consultant (Durkan et al, 2006;Simckes et al, 2000), and between an intraperitoneal and extraperitoneal graft in the case of allograft percutaneous biopsies (Vidhun et al, 2003).…”

“…In rare cases of children with serious contraindication or objection to sedation or anesthesia, ''verbal sedation'' has been used, with the child talked through the procedure with the help of a child life specialist trained in this approach (Hussain et al, 2003). Case series from North American centers show that general anesthesia is most often reserved for infants or very small children where lack of cooperation during the procedure is a concern as well as in children whose airways may be at risk with sedation alone (Birk et al, 2007;Simckes et al, 2000;Sweeney et al, 2006). This approach is not necessarily the case worldwide and, in fact, a recent audit in the United Kingdom (Hussain et al, 2010) showed 6 of 11 centers routinely using general anesthesia for pediatric kidney biopsies.…”

“…There have been no major adverse events reported with this protocol and both patient and family satisfaction rates have been high. Other published sedation protocols employ a combination of meperidine (1 mg/kgmaximum 50 mg) and diazepam (0.2-0.4 mg/kg), with ketamine reserved for additional sedation if necessary (Hussain et al, 2003); midazolam 0.1 mg/kg with additional ketmaine where required (Mahajan et al, 2010); or intravenous propofol (1 mg/kg/dose titrated to effect) and fentanyl (1 µg/kg/dose) (Birk et al, 2007). Again, local practice and clinician familiarity and expertise with certain medications tend to influence the type of sedation provided most successfully and is more critical than the use of any specific medication or combination of medications.…”

“…Over the last two decades, with increasing safety of percutaneous renal biopsy, particularly when performed with an automated biopsy needle under real time ultrasound guidance, more centers are moving towards short post-biopsy monitoring times for both native and allograft renal biopsies in children. In fact, several centers in North America and Europe have implemented same day renal biopsy in ambulatory or day clinical care units as standard practice for low risk patients since the early 1990s (Birk et al, 2007;Hussain et al, 2003;Sweeney et al, 2006). This trend has been associated with significant cost savings compared to inpatient renal biopsies and comparable safety outcomes (Chesney et al, 1996;Hussain et al, 2003;Lau et al, 2009;Simckes et al, 2000).…”

“…Following the biopsy, patients are typically monitored for 6-8 hours with strict bed rest for 1-3 hours. Patients are discharged home at the end of this observation period if their urine is free of gross hematuria, their vital signs are stable and they have no significant pain at the biopsy site (Birk et al, 2007;Hussain et al, 2003;Ogborn & Grimm, 1992;Simckes et al, 2000). The value of routine post-biopsy imaging studies is controversial, with several studies suggesting the development of post biopsy perinephric hematomas is common and does not negatively impact patient outcomes or change the need for patient care in most cases (Castoldi et al, 1994;Vidhun et al, 2003).…”