Preoperative renal scar as a risk factor of postoperative metabolic acidosis following ileocystoplasty in patients with neurogenic bladder.
OBJECTIVE
We investigated relation of preoperative renal scar to incidence of postoperative metabolic acidosis following ileocystoplasty in patients with neurogenic bladder.


METHODS
Thirty patients with neurogenic bladder, who underwent ileocystoplasty, were enrolled in the present study. Median age at ileocystoplasty was 13.9 years and median follow-up period after ileocystoplasty was 8.2 years. Metabolic acidosis was defined based on the outlined criteria: base excess (BE) is less than 0 mmol l(-1). Preoperative examination revealed that no apparent renal insufficiency was identified in blood analysis, although preoperative (99m)Tc-DMSA scintigraphy indicated abnormalities such as renal scar in 14 patients (47%). Incidence of postoperative metabolic acidosis was compared between patients with and without preoperative renal scar, which may reflect some extent of renal tubular damage.


RESULTS
Postoperative metabolic acidosis was identified in 13 patients (43%). Incidence of postoperative metabolic acidosis was significantly higher in patients with renal scar (11/14, 79%) compared with patients without renal scar (2/16, 13%; P<0.01). Particularly, all eight patients who had bilateral renal scars showed metabolic acidosis postoperatively. Compared with patients without preoperative renal scar, pH (P<0.05) and BE (P<0.01) were significantly lower postoperatively in patients with preoperative renal scar. However, there was no significant difference in PCO2. Hyperchloremia was observed in each patient with or without preoperative renal scar.


CONCLUSIONS
Incidence of postoperative metabolic acidosis was significantly implicated in preoperative renal scar. If renal abnormalities are preoperatively identified in imaging tests, we need to care patients carefully regarding metabolic acidosis and subsequent comorbidities following ileocystoplasty.
Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
T
T
Mitsui
Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
K
K
Moriya
Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
T
T
Kitta
Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
M
M
Kon
Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
K
K
Nonomura
D000138:Acidosis / Q000097:blood / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002921:Cicatrix / Q000000981:diagnostic imaging / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D011300:Preoperative Care; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012307:Risk Factors; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D001750:Urinary Bladder, Neurogenic / Q000097:blood / Q000000981:diagnostic imaging / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000009:adverse effects; D055815:Young Adult
D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid