回復期脊髄損傷における膀胱結石の臨床検討

Abstract

過去2年間の回復期脊髄損傷症例190例(平均年齢54.7歳)を対象に, 膀胱結石の発生率とその要因を検討した。その結果, 31名16.3%に膀胱結石を認め, 摘出術を要した。受傷から手術までの期間は79～276日, 中央値163日であった。結石のある群とない群とでは, 尿pH, 尿中から同定された菌種, 排尿方法に有意差を認めなかった。急性期の尿道カテーテル留置期間に統計学的有意差を認め, カテーテルを4週間以内で抜去できた症例では摘出が必要な結石を認めなかった。結石は多数で皿状の薄いものが多かった。結石成分の含有率は様々であったが, 結石症例の70%に燐酸マグネシウムアンモニウム(MAP)結石を含有していた。脊髄損傷受傷急性期には可能な限り早期のカテーテル抜去を心がけるべきであると考えた。

Bladder stones that form in patients with spinal cord injury in the subacute stage can cause significant morbidity. In this retrospective study, we investigated the factors associated with bladder stone formation. The study population consisted of 141 men and 24 women (median age: 59 years) who were admitted to our hospital for rehabilitation, from January 2005 to December 2006. We investigated urinary pH, bacterial species in urine and duration of indwelling urethral catheter in the acute stage after spinal cord injury. Thirty-one patients (16.3%) were diagnosed with bladder stones and underwent transurethral lithotripsy. Compared with patients without bladder stones, the duration of the indwelling catheter was longer in patients who bladder stones, but there was no difference between the two groups regarding urinary pH and the bacterial species found in urine. None of the patients for whom the duration of the indwelling catheter was less than a month developed bladder stones. These results suggest that long duration of the indwelling urethral catheter is a risk factor for the development of bladder stones. This information should be taken into account to reduce the occurrence of bladder stones and patients' morbidity.