Background. Abdominal aortic aneurysms (AAA) requiring surgical management are encountered more frequently in renal transplant recipients, presenting an important technical problem during the repair. The aim of the present study was to analyze the epidemiology and natural evolution of AAA among renal allograft recipients.Methods. Three hundred ninety-four renal transplant recipients were periodically evaluated with abdominal aortic ultrasound tomography for AAA. The indication for surgery was a maximal diameter > 5 cm. Renal function, graft, and patient survival were evaluated after a mean follow-up of 51 months.Results. Four AAA were detected in 394 renal transplant recipients, a prevalence of 1.01%. All of the AAA were found in male recipients of mean age 59.2 +/- 5.5 years and mean time posttransplantation of 82.7 +/- 77.3 months. The mean follow-up period between diagnosis and indication for surgery was 14.2 +/- 10.8 months. Two patients underwent open repair with aneurysmectomy and conventional tube graft positioning, and 2 patients refused surgical repair. To preserve renal graft function during the aortic cross-clamping phase, cold perfusion with 4 degrees C Ringer acetate and local hypothermia with sterile ice were used. Renal function did not change after the operation (preoperative serum creatinine levels were 1.2 and 1.3 mg/dL; postoperative 1.3 and 1.5 mg/dL respectively). The 2 patients who underwent surgery are alive with excellent graft functioning after a follow-up of 1.5 and 7 years, respectively. The 2 patients who refused surgical treatment are dead.Conclusions. Yearly ultrasound screening for AAA must be recommended in renal transplant recipients as part of the routine posttransplantation follow-up. De novo AAA occurs in younger subject in the transplant population and shows a faster evolution.

The development of plastic fiberoptic catheters, cheaper and less fragile than glass ones, has enabled the more widespread use of oxyhaernoglobin saturation (So2) monitoring. They allow direct determinations of SO2 to be made, using reflection spec trophotome try.

Pocidalo, J. J.; Tremolieres, F.; Olsson, S. G.; Vallois, J. M.; Chirico, A. Author Information

Two electrodes placed at the tip of catheters forin vivo determinations of $${\text{P}}_{{\text{CO}}_{\text{2}} } $$ and $${\text{P}}_{{\text{O}}_{\text{2}} } $$ respectively, were tested in dogs. Results were satisfactory when compared to a highly accurate reference method, correlation coefficients were close to 1 (P -9). Means of the differences were respectively -1.74 ± 1.14 torr for the $${\text{P}}_{{\text{O}}_{\text{2}} } $$ probe (P < 0.01) and -1.62 ± 0.72 torr for the $${\text{P}}_{{\text{CO}}_{\text{2}} } $$ sensor (P < 0.0001). While no drift was detected in the $${\text{P}}_{{\text{CO}}_{\text{2}} } $$ electrode that of the $${\text{P}}_{{\text{O}}_{\text{2}} } $$ was significant but negligible compared to the variability of measurements. Thus, for $${\text{P}}_{{\text{CO}}_{\text{2}} } $$ values between 20 and 85 torr, and $${\text{P}}_{{\text{O}}_{\text{2}} } $$ values between 20 and 140 torr,in vivo monitoring is sufficiently reliable for clinical use.

Two electrodes placed at the tip of catheters for in vivo determinations of PCO2 and PO2 respectively, were tested in dogs. Results were satisfactory when compared to a highly accurate reference method, correlation coefficients were close to 1 (P less than 10(-9)). Means of the differences were respectively --1.74 +/- 1.14 toor for the PO2 probe (P less than 0.01) and --1.62 +/- 0.72 torr for the PCO2 sensor (P less than 0.0001). While no drift was detected in the PCO2 electrode, that of the PO2 was significant but negligible compared to the variability of measurements. Thus, for PCO2 values between 20 and 85 torr, and PO2 values between 20 and 140 torr, in vivo monitoring is sufficiently reliable for clinical use.