Salvage operations for malfunctioning polytetrafluoroethylene hemodialysis access grafts.

During the study period a cohort of 170 of patients receiving long-term hemodialysis treatment required placement of 214 polytetrafluoroethylene grafts for vascular access; within this period 74 of these patients had significant graft malfunction that required 149 salvage operations. The most common failure/malfunction was thrombosis, and the most commonly appreciated mechanical cause of graft failure was outflow venous stenosis. Complex revisions were required to address this problem. First, second, and third revisions were successful in 65%, 53%, and 44% of cases, respectively. Multiple revisions, including thrombectomy, were required in some, but the functional life of these salvaged grafts was nearly equal to that of grafts that did not require revision. Abandonment of grafts because of secondary infection exacted a toll in both groups.

Significance of microbial contamination of stored cadaver kidneys.

The importance of microbial contamination of cadaver kidneys was assessed in 83 consecutively stored and transplanted kidneys. Fourteen kidneys had a single positive culture during storage and five had multiple positive cultures. Only one postoperative infection could be traced to kidney contamination during storage (Candida wound infection). In three of 64 patients who received noncontaminated kidneys, posttransplant wound infections developed. No wound infections occurred in 35 patients who received prophylactic antibiotics, whereas four wound infections occurred in 48 patients without antibiotic coverage. It is concluded that, although microbial contamination of stored cadaver kidneys occurs commonly, it is not an important source of infection in renal transplant recipients.

Renal injury by companion kidney during hypothermic pulsatile perfusion.

To study possible deleterious effects of traumatized kidneys on well harvested ones during hypothermic pulsatile perfusion, paired dog kidneys were monitored on two separate MOX-100 machines connected to pool a common perfusate. First kidneys were optimally harvested and baseline renal vascular resistance (RVR) calculated from pressure divided by flow (mm Hg/ml minute). After 1 hour second kidneys were added and observation was continued for an additional 3 hours. RVR in first kidneys increased immediately and doubled by 3 hours when ischemic traumatized second kidneys were added, 0.70 +/- 0.07 to 1.37 +/- 0.15 (p less than 0.001). No change in RVR was noted when second kidneys were optimally retrieved or if the dogs were heparinized prior to nephrectomy. Histological examination showed no evidence of vascular obstruction in any kidney, but only tubular necrosis in nonheparinized, traumatized second kidneys. Weight gain in optimally removed kidneys was 41%, but only 8% in ischemic kidneys. RVR decreased unexpectedly in ischemic kidneys during 3 hours of perfusion (p less than 0.01). Release of vasoactive substances by damaged kidneys and arteriovenous shunting may explain these findings. Separate perfusion systems seem to be justified when one of two cadaver kidneys is of marginal quality.