Fluorescence spectroscopy in renal ischemia and reperfusion: noninvasive evaluation of organ viability

BACKGROUND

Damage provoked by ischemia in renal transplants is difficult to quantify. To determine whether a donated organ is fit for transplantation. We sought to correlate the findings of fluorescence spectroscopy (FS) with histologic evidence of ischemic injury and organ viability.

METHODS

Kidneys of 33 rats were submitted to FS of the upper and lower poles as well as the middle third. Excitation was generated by the laser's wavelengths of 408, 442, and 532 nm. Rats were randomized into groups with the 30, 60, and 120 minutes warm ischemia before analysis by FS, that was repeated at 5 minutes after reperfusion.

RESULTS

FS results in the reperfusion phase correlated with ischemia time and degree of histologic injury. After 60 or 120 minutes of ischemia, the excitation lasers of 532 and 442 nm resented a significant negative correlation coefficient with the histological grade (r = -0.61 and r = -0.73, respectively).

CONCLUSIONS

There was a strong correlation between FS and histologic changes only in the reperfusion phase after renal ischemia. The method was thus unable to assess the viability of organs before transplantation.

Evaluation by fluorescence spectroscopy of the most appropriate renal region for obtaining biopsies: a study in the rat

INTRODUCTION

Renal puncture biopsies are directed at the lower poles of the organ to decrease the risk of hemorrhage and complications.

OBJECTIVES

To evaluate by fluorescence spectroscopy (FS) the most appropriate renal region (in terms of metabolic changes) to obtain a biopsy.

MATERIALS AND METHODS

The kidneys of 33 Rattus norvegicus rats were submitted to FS detection in the upper and lower poles and in the middle third. Excitations were generated with lasers at wavelengths of 408, 442, and 532 nm. Animals were divided at random into groups of warm ischemia (30, 60, and 120 minutes), whose kidneys were again analyzed by FS, as well as after 5 minutes of reperfusion using the same excitation beams in the same renal regions. Then the kidneys underwent histologic preparation and examination.

RESULTS

The middle third area of the rat's kidneys proved to be significantly more sensitive to ischemic and reperfusion changes than the renal poles, as determined by FS (P < .001).

CONCLUSIONS

The middle third of the kidney was the most appropriate site for a renal biopsy to monitor a transplanted organ.

Therapeutic option for infected urinary tract fistulas in renal transplantation

BACKGROUND

Approximately 20% of urinary tract fistulas after renal allografting are complicated by urinary tract infection, which presents a therapeutic challenge.

OBJECTIVE

To evaluate an option for treatment of urinary tract fistulas associated with urinary tract infection and unsuitable for minimally invasive or primary surgical urinary tract repair.

PATIENTS AND METHODS

The study included 650 recipients who underwent transplantation over 17 years. Urinary leakage was initially treated with indwelling bladder catheterization. Patients with fistulas refractory to treatment underwent surgical intervention to repair the urinary tract. In patients who were not candidates for primary repair of the urinary tract, temporary urinary diversion was performed, rather than classic percutaneous or open nephrostomy, using a ureteral stent (ie, a 6F or 8F Foley catheter with the balloon placed inside the renal pelvis).

RESULTS

Overall, urinary leakage occurred in 36 patients (5.5%). Conservative management was successful in 14 vesical fistulas (42.4%) and no ureteral fistulas (0%). Three patients died of sepsis during conservative treatment, before the new surgical approach. Five of 36 urinary leaks (13.9%) were managed using ureteral intubation with an 8F Foley catheter, with a success rate of 80%.

CONCLUSION

Ureteral catheterization with an 8F Foley catheter is a feasible therapeutic option to treat complicated urinary tract fistulas unsuitable for primary surgical repair of the urinary tract.