ENDOSCOPIC SUBURETERAL INJECTION TREATMENT WITH CALCIUM HYDROXYLAPATITE IN PRIMARY VESICOURETERAL REFLUX

Abstract

Abstract

Introduction: During the last 20 years endoscopic treatment of vesicoureteral reflux (VUR) has gained

popularity. However the choice of injection material to be used is controversial. Calcium hydroxylapatite

(Coaptite®) biocompatible injectable material has been reported to be a promising alternative to other tissue

augmenting substances. Coaptite® is composed of microspheres of calcium hydroxylapatite, the same material

that is a major component of bone and teeth. In this study, we evaluated results of subureteric injection of

calcium hydroxylapatite treatment for primary vesicoureteral reflux.

Materials and Methods: Twenty three children (mean age 6.6±2.9 years) underwent subureteral injection

of calcium hydroxylapatite for primary vesicoureteral reflux between April 2002 and April 2004. Reflux was

unilateral in 9 cases and bilateral in 14 of affected 37 ureteral units. Preoperative urine culture, renal

ultrasonography, static renal sintigraphy (DMSA) and voiding cystouretrography were performed in all cases.

According to “International Reflux Classification”; grade I reflux in 5 (13.5%), grade II in 9 (24.3%), grade

III in 15 (40.5%), grade IV in 7 (18.9%) and grade V in 1 üreteral unit (2.7%) was found. Wide spectrum

antibiotics were given to all cases before operation. Under general anesthesia, following routine cystoscopy in

dorsal lithotomy position all patients underwent endoscopic subureteral injection with calcium

hydroxylapatite. Under direct vision through the 11 F cystoscope needle tip is inserted at the 6 o’clock position

into the subureteric space, approximately 0.5 cm distal to the ureteral orifice. A correctly placed injection

creates the appearance of a nipple and in order to avoid extravasation, from a single entrance. Following

injection, after waiting for one minute needle was taken out and procedure was completed. Treatment was

done on an outpatient basis. Average injected volume was 1.3 ml for per ureteral unit. Median follow-up was

11.3 months (range 8 to18 months). Antibiotic prophylaxis was prescribed for 12 weeks after the procedure.

Renal sonography was performed in four weeks to determine whether hydronephrosis was present. Success of

treatment was assessed by voiding cystourethrographies at 3rd and 12th month after subureteric injection.

Results: The reflux was corrected in 20 (54.1%) ureteral units after a single injection and resolved after a

second and third injection in 3 and 2 ureteral units, respectively. However, total success rate of reflux

treatment with calcium hydroxylapatite was 67.6% in all ureteral units; the success rate was approximately

80% in patients with grade I-III VUR. Endoscopic treatment failed to correct reflux in 12 ureteral units, which

were managed by ureteral reimplantation. No procedure related complications and untoward effects were

observed in any patients in whom calcium hydroxylapatite was used as the injected material. In cases that

showed cure by cystouretrography at 3rd month, reflux recurrence was not observed by cystouretrography on

12th month.

Conclusion: Endoscopic subureteral injection of calcium hydroxylapatite in children with primary low

grades vesicoureteral reflux appears to be an effective, safe and minimally invasive technique. In addition,

procedure is extremely simple and no additional equipment is required.