Results of extracorporeal shock wave lithotripsy for the treatment of upper urinary tract stones

Abstract

The treatment results of 697 renal units in 687 patients treated for upper urinary tract stones using a Piezolith 2500 at the Ageo Central General Hospital during the 5-year period between August 1999 and July 2004 were analyzed. The stone-free rate and the success rate were calculated according to the stone size and location. Univariate and multivariate logistic regression analyses were performed to estimate the effect of the patient age, sex, affected side, stone location and stone size on the stone-free rate and the success rate. Overall, the stone-free rate and the success rate at 3 months after treatment were 82.6% and 91.9%, respectively. The stone-free rates in renal and ureteral stones were 60.5% and 88.7%, respectively. The success rates for renal and ureteral stones were 93.6% and 91.6%, respectively. In a univariate logistic regression analysis, patient age and stone size were significant negative factors for both the stone-free rate and the success rate and the stone location in ureter was a significant positive factor only for the stone-free rate. In a multivariate analysis, stone location in the ureter had a positive effect on the stone-free rate, although a negative effect on the success rate. Extracorporeal shock wave lithotripsy for upper urinary tract stones was an effective and safe treatment modality. However, if pre-treatment factors indicate unfavorable outcome, the other treatment options should be considered for the first line therapy.

1999年8月から2004年7月までの5年間に上尾中央総合病院でPiezolith 2500を用いて体外衝撃波腎尿管砕石術を施行された687症例, 697腎尿管の治療成績を検討した。結石の大きさ, 部位による完全排石率と有効率を算出した。患者の年齢, 性別, 患側, 結石の部位, 結石の大きさの完全排石率, 有効率に対する影響を推定するため単変量および多変量ロジスティック回帰分析を行った。全症例で3ヵ月後の完全排石率および有効率はそれぞれ82.6%および91.9%であった。腎結石および尿管結石での完全排石率はそれぞれ60.5%および88.7%であった。腎結石および尿管結石での有効率はそれぞれ93.6%および91.6%であった。単変量ロジスティック回帰分析では患者の年齢と結石の大きさが完全排石率, 有効率の両方を低下させる要因であった。結石が尿管にあることは完全排石率のみを有意に改善させる要素であった。多変量解析では結石が尿管にあることは完全排石率を改善させるが, 有効率は低下させる要因であった。体外衝撃波砕石術は上部尿路結石に対する有効で安全な治療法である。しかし, 治療前の要因から好ましくない結果が予想される場合は他の治療法を検討すべきと思われる。(著者抄録)