Absorption of glycine irrigating solution during endoscopic transanal resection of rectal tumors.

Purpose: This study was undertaken to evaluate the potential metabolic complications of 1.5 percent glycine irrigating solution during endoscopic transanal resection (ETAR) of rectal tumors.

Methods: Thirteen consecutive frail patients (mean age, 81 (range, 57-91) years) undergoing 18 ETAR were prospectively studied from July 1993 to January 1995. Indications for ETAR included palliation of advanced rectal cancer (12 patients) and an extensive villous tumor (1 patient). A 27-French two-way Iglesias resectoscope was used. Packed cell volume, blood glucose, and serum concentrations of sodium, potassium, and creatinine were measured before, during (at 45 minutes), and after (at 6 and 24 hours) ETAR. Plasma concentration of glycine and hemoglobin levels were both measured preoperatively and at 45 minutes and 24 hours, respectively. Variables studied included resection time, volume and rate of irrigating fluid, height of irrigating fluid bag above operating table, resectate weight, occurrence of intraperitoneal and extraperitoneal perforation, blood loss, and clinical symptoms.

Results: Two patients were excluded. Mean operating time was 456 minutes. A mean of 192.3 liters of irrigant was infused into the rectum. Mean irrigation rate was 43,330 ml/minutes. Mean height of irrigating fluid bag was 692 cm. Extraperitoneal perforation occurred in two patients. Blood loss exceeded 200 ml in four patients, one of whom complained of nausea (operating time, 110 minutes). Mean rise in p-glycine at 45 minutes (10,028 mol/l; 387 percent of preoperative values) was significant (P = 0.006). Changes in packed cell volume, b-hemoglobin, b-glucose, s-sodium, and s-creatinine levels were not significant. There was significant correlation between p-glycine and s-creatinine levels at six hours (P = 0.033), between p-glycine levels and fall in s-sodium at 24 hours (P = 0.037), and between levels of b-hemoglobin and packed cell volume at 24 hours (P = 0.0004). There was a positive linear correlation between p-glycine and operating time (r = 0.7; P = 0.0026) and between p-glycine and volume of irrigating fluid (r = 0.5; P = 0.0386).

Conclusions: Operating time best predicts increase of p-glycine in ETAR.