Maintaining urine production and early allograft function during laparoscopic donor nephrectomy.

OBJECTIVES: Intraoperative oliguria and its impact on early postoperative allograft function have been expressed as potential concerns of laparoscopic kidney donation. We evaluated our ability to maintain adequate diuresis during laparoscopic donor nephrectomy and its potential impact on early graft function compared with open donation. METHODS: We performed a retrospective review of 98 laparoscopic and 80 open donor nephrectomies from 1999 to 2002. All laparoscopic donors received infusions of mannitol (grams of mannitol equaled patient weight in kilograms) and dopamine (2 to 3.0 microg/kg/min) throughout the pneumoperitoneum. All open donors received a single dose of mannitol (12.5 g). Multiple donor variables were compared, including operative time, estimated blood loss, intraoperative fluid administration (in milliliters per kilogram per hour), intraoperative urine production (milliliters per kilogram per hour), and change in creatinine at discharge. The postoperative recipient data were compared, including initial 24-hour urine output, 1-week creatinine level, 1-month creatinine level, and need for postoperative hemodialysis. RESULTS: No significant differences were noted in the donor groups with respect to age, weight, intraoperative fluid administration, or change in creatinine at discharge. The mean operative urine production was greater in the laparoscopic group at 5.22 mL/kg/hr than in the open group at 2.43 mL/kg/hr (P = 0.0001). The mean estimated blood loss was significantly lower (P = 0.0001) for the laparoscopic donors (106.7 mL) than for the open donors (184.7 mL). No significant differences were seen among the recipient groups. CONCLUSIONS: The use of mannitol and dopamine infusions during laparoscopic donor nephrectomy provided superior intraoperative urine production in the donor and equivalent early graft function in the recipient compared with the open approach.

Magnetic resonance imaging findings after laparoscopic renal cryoablation.

OBJECTIVES: To assess the magnetic resonance imaging (MRI) appearance of renal masses after laparoscopic cryoablation. METHODS: Between October 2000 and June 2004, 33 patients underwent laparoscopic cryoablation of 34 renal masses, 24 of whom (25 renal masses, size range 1.5 to 3.7 cm, mean 2.4) were followed up with MRI postoperatively. Postoperative MRI was done at 1, 3, and 6 months after ablation and every 6 months thereafter using a 1.5-T MRI scanner. T1-weighted dual-phase, coronal T1-weighted fat-saturated, and T2-weighted coronal and axial MRI was done before contrast administration. Postenhancement images were obtained in the coronal and axial planes during the arterial, venous, and delayed phases. RESULTS: Patient follow-up data were available for at least 6 months and up to 48 months for 18 patients. On the first follow-up MRI study, six lesions had increased in size, five had decreased in size, and seven showed no change. Of the 18 patients, 7 had peripheral rim enhancement within 3 months of follow-up. Four resolved. One patient developed rim enhancement at 7 months postoperatively. Subsequent images revealed lesion enlargement with heterogeneous enhancement. Biopsy was positive for renal cell carcinoma. One patient developed nodular enhancement at 10 months with a decrease in lesion size. Watchful waiting was chosen because the patient had significant medical comorbidities. CONCLUSIONS: Peripheral rim enhancement is a common finding on MRI immediately after laparoscopic renal cryoablation. Rim enhancement with an increase in lesion size or nodular enhancement is of more concern than rim enhancement alone. More data are necessary to understand the progression of renal lesions after cryoablation.