**2.2.2.1 Imperative indications**

Is there an impact of imperative indications for NSS on peri-operative complications? In a study by Cofin, no significant difference was seen between elective and imperative indications regarding operating time, but the elective group had better surgical outcomes: less blood loss and better control of post-operative creatinin level (Coffin 2011). For oncologic outcomes, Antonelli (Antonelli et al., 2008) found a lower recurrence rate and a higher disease free survival rate at 5 years in elective indications compared with imperative indications.

#### **2.2.2.2 Elderly**

Being older than 65 years does not seem to be a significant prognostic factor for having surgical as well as medical complications after partial nephrectomy. The difference was statistically significant for cardiac complications only (Roos et al., 2010).

The Role of Nephron-Sparing Surgery (NSS) for Renal Tumours >4 cm 335

Clamping is necessary to resect the tumour in a bloodless field, to minimise intra-operative blood loss, to contribute to a better vision during dissection and to facilitate renorraphy. Ischemia induces endothelial lesions which lead via multi-inflammatory response to vasoconstriction and vasospasms and thus ischemia. The low renal blood flow induces renal cell lesions and subsequent release of angiotensin II and eicosanoids. During ischemia, there is a failure of oxidative phosphorylation and depletion in adenosine triphosphate (ATP). It causes cellular swelling by passive diffusion of water into cells. Cell swelling prevents reperfusion when unclamping (no reflow phenomenon) and ATP degradation produces free

For warm ischemia, maximal clamping time to preserve renal function was previously thought to be less than 31 minutes. Later it was suggested to try to limit warm ischemia time to less than 20 minutes (Becker et al., 2009). But Thompson goes further and states that "every minute counts". In his retrospective study, he analysed 362 patients with solitary kidneys and demonstrated that 25 minutes is the best cut-off for clamping time to make the distinction of patients at risk for acute renal failure, a GFR < 15ml /min per 1.73 m² and new-onset stage IV chronic kidney disease during follow up. Each additional minute increased this risk. The same cut off for irreversible renal damage was found in a

Thus we should consider 20-25 minutes to be the best cut-off to avoid adverse renal consequences, keeping in mind the shorter the clamping time the better. We should not forget that even with extended ischemia, partial nephrectomy still offers better renal

Regarding clamping technique, Coffin did not observed a difference in postoperative renal

There is no consensus for type of clamping: arterial or "en bloc" arterial and venous clamping. It is also not known whether intermittent clamping is better than continuous.

Kidney cooling prior to clamping can prevent cell damage. The optimal temperature to

When ischemia time is estimated to be probably more than 25 minutes, cold ischemia is a good option. The principle is to cool the kidney with ice slush for 10 minutes, after which the hilum should be clamped. Nevertheless, also cold ischemia time must be limited to the minimum. A maximum of 35 minutes has been proposed by several authors (Thompson et

In order to reduce the impact of ischemia, it is advised to provide preoperative hydration to facilitate renal perfusion and stimulate urine production. Therefore, furosemide administered intra-operatively is useful. Intravenous mannitol at a dose of 1 ml/kg has also been proven to be beneficial for optimal reperfusion (Becker et al., 2006). Weizer and his

radicals which cause further cell damage (reperfusion injury).

**2.3.2.1 Impact of clamping time** 

prospective study (Funahashi 2009).

**2.3.2.2 Impact of clamping technique** 

achieve this seems to be 15°C (Becker 2009).

**2.3.2.4 Pharmacologic strategies** 

**2.3.2.3 Cooling** 

al 2007).

function outcomes compared to RN (Lane et al., 2010).

function between mechanical and digital clamping of the pedicle.
