Nephrotoxicity Associated to Parenchymal Clamping During Partial Nephrectomy Using a Microdialysis Technique

Assessment of Nephrotoxicity Associated to Parenchymal Clamping During Partial Nephrectomy Using a Microdialysis Technique: NECPAR Study

Surgery plays a central role in kidney cancer management being the only therapy that offers the possibility of healing the patients. Currently, the partial nephrectomy is a standard technique because it meets the principle of nephron sparing surgery. A partial nephrectomy requires a control of the renal blood flow using a clamp, which can be parenchymal or vascular (pedicular). In France, most of the centers use pedicular clamping. It is well established that this technique results in warm ischemia of the entire healthy parenchyma and can lead to permanent kidney damages. Currently, no study evaluated the impact of parenchymal clamping on the healthy parenchyma.

The aim of the investigators study is to evaluate the nephrotoxicity of the healthy parenchyma due to parenchymal clamping during partial nephrectomy. This assessment will be done through a microdialysis technique. The microdialysis probe is directly implanted in the healthy unclamped parenchyma and will allow us to measure in real time, during the surgery, the biological changes related to anaerobic metabolism of renal interstitial space. All those measures will be completed by urinary and plasmatic assessments. Oxidative stress will be assessed using four markers of tubular viability : Interleukin 18 (IL18), Kidney Injury Molecule-1 (KIM-1), Neutrophil Gelatinase-Associated Lipocalin (NGAL) and cystatin C and four parameters of anaerobic metabolism : lactate, pyruvate, glycerol and glucose.

This is a prospective pilot study limited to 10 patients included over 12 months. Depending on the results, it will be further developed by a second study comparing parenchymal with pedicle clamping.

Inclusion Criteria:

• Patients referred to the urological surgery department with an indication of partial nephrectomy
• Patients with a renal lesion classified T1 (≤7cm) or for T2 eligible to a partial nephrectomy and having an possibility to benefit from a parenchymal clamping (decided on preoperative imaging)

Exclusion Criteria:

• Patient with a chronic kidney disease (functional or structural renal abnormality evolving for more than three months and Glomerular Filtration Rate <60 ml/min)
• Patient carrying a renal lesion classified T1 but too close to the renal pedicle or not accessible for a parenchymal clamping
• Patients in whom tumor removal requires ice cooling or kidney pedicular clamping