**3.2.1 Surgical aspects**

#### **3.2.1.1 Transperitoneal versus retroperitoneal approach**

62% of the tumours were operated transperitoneally in the study of Patel (Patel et al., 2010). Porpiglia (Popiglia et al., 2010) observed a higher rate of the transperitoneal approach for tumors larger than 4 cm, with no higher rate of conversion to open surgery.

#### **3.2.1.2 Resection technique**

Most surgeons performing laparoscopic NSS prefer an enucleo- resection: excision of the tumour with a thin layer peritumoral healthy parenchyma (Porpiglia et al., 2010). In several studies, a laparoscopic ultrasound probe was used to identify the lesion intraoperatively (Porpiglia et al., 2010; Patel et al., 2010), even when it concerned large renal tumours (> 4 cm).

#### **3.2.1.3 Impact of clamping technique and time on renal function**

In all the centres of the study by Porpiglia, the renal artery was clamped alone (Porpiglia et al., 2010).

Patel described clamping of both, the artery and the vein in case of large, endophytic and central tumors. On the other hand, the artery alone is clamped for small, peripheral or cortical tumors (Patel et al., 2010).

To prevent vascular injury, bulldog clamps are preferred to a Satinsky clamp, even though the true benefit of this approach remains to be proven (Weizer et al., 2011). Some surgeons use vessel loops with a hem-o–lock as clamp in order to prevent pedicle lesions.

To prevent renal function loss, Shao (Shao et al, 2011) proposed another technique consisting in selective clamping of the feeding segmental renal artery. This technique demands a larger dissection to expose 2-3 arterial branches for selective clamping. The demarcation line of the parenchymal ischemia is observed to ensure the resection area is clamped. In case the ischemic area does not encompass the tumour, multiple segmental arteries are clamped. Patients with tumours larger than 4 cm were included if their resection was estimated feasible. There were 11 cT1b tumours operated: respectively 5 operated with main renal artery clamping and 6 with selective clamping. Of, the latter group, half of them had to be converted to main renal artery clamping. There was a significant increase in operative time, blood loss and warm ischemia time in the selective clamping. 3 months post-operatively, GFR was estimated with a camera-based method measuring the renal uptake of technetium 99m diethylenetriaminepentaacetic acid. The GFR reduction of the affected side was significantly less with selective clamping. Half of the tumours larger than 3.5 cm tumours required clamping of 2 or more segmental arteries. Complication rate was acceptable. This technique seems not really appropriate for large tumours given the high conversion rate.

Simple enucleation can be performed for tumours larger than 4 cm. Long-term outcomes are

Laparoscopic partial nephrectomy (LPN) offers the benefits of a minimal invasive approach

62% of the tumours were operated transperitoneally in the study of Patel (Patel et al., 2010). Porpiglia (Popiglia et al., 2010) observed a higher rate of the transperitoneal approach for

Most surgeons performing laparoscopic NSS prefer an enucleo- resection: excision of the tumour with a thin layer peritumoral healthy parenchyma (Porpiglia et al., 2010). In several studies, a laparoscopic ultrasound probe was used to identify the lesion intraoperatively (Porpiglia et al., 2010; Patel et al., 2010), even when it concerned large renal tumours (> 4 cm).

In all the centres of the study by Porpiglia, the renal artery was clamped alone (Porpiglia et

Patel described clamping of both, the artery and the vein in case of large, endophytic and central tumors. On the other hand, the artery alone is clamped for small, peripheral or

To prevent vascular injury, bulldog clamps are preferred to a Satinsky clamp, even though the true benefit of this approach remains to be proven (Weizer et al., 2011). Some surgeons

To prevent renal function loss, Shao (Shao et al, 2011) proposed another technique consisting in selective clamping of the feeding segmental renal artery. This technique demands a larger dissection to expose 2-3 arterial branches for selective clamping. The demarcation line of the parenchymal ischemia is observed to ensure the resection area is clamped. In case the ischemic area does not encompass the tumour, multiple segmental arteries are clamped. Patients with tumours larger than 4 cm were included if their resection was estimated feasible. There were 11 cT1b tumours operated: respectively 5 operated with main renal artery clamping and 6 with selective clamping. Of, the latter group, half of them had to be converted to main renal artery clamping. There was a significant increase in operative time, blood loss and warm ischemia time in the selective clamping. 3 months post-operatively, GFR was estimated with a camera-based method measuring the renal uptake of technetium 99m diethylenetriaminepentaacetic acid. The GFR reduction of the affected side was significantly less with selective clamping. Half of the tumours larger than 3.5 cm tumours required clamping of 2 or more segmental arteries. Complication rate was acceptable. This technique seems not really

use vessel loops with a hem-o–lock as clamp in order to prevent pedicle lesions.

tumors larger than 4 cm, with no higher rate of conversion to open surgery.

**3.2.1.3 Impact of clamping technique and time on renal function**

appropriate for large tumours given the high conversion rate.

comparable to standard NSS.

**3.2.1 Surgical aspects** 

**3.2.1.2 Resection technique** 

cortical tumors (Patel et al., 2010).

al., 2010).

**3.2 Laparoscopic partial nephrectomy** 

together with the benefits of preserving renal function.

**3.2.1.1 Transperitoneal versus retroperitoneal approach** 

A critique to the laparoscopic approach remains that ischemia time is usually longer than in open procedure. In a European survey (Porpiglia et al., 2010), mean warm ischemia time was 25.7 minutes with a range 15-46 minutes. Cooling techniques in laparoscopy are time consuming. Clamping usually lasts from the beginning of the resection to the end of parenchymal suture. In order to reduce warm ischemia time, Nguyen (Nguyen et al., 2008) proposed to remove the clamp after the first layer of parenchymal suture. The remaining renorrhaphy is thus performed in the revascularized kidney. This technique decreases warm ischemia time by over 50%. There was a trend towards improved outcomes: less overall complications (16% vs. 22%), less postoperative renal haemorrhage (2% vs. 4%) and a decreased re-intervention rate (6% vs. 16%). However, those differences were not statistically significant. No patient had a positive resection margin, required open conversion or showed renal dysfunction.

### **3.2.1.4 Impact of parenchymal suture on renal function**

The goal of efficient renorraphy is to reduce warm ischemia time. The type of suture (running of interrupted) is not correlated with longer warm ischemia time.

Fig. 4-5. Examples of interrupted suture in open surgery.

The Role of Nephron-Sparing Surgery (NSS) for Renal Tumours >4 cm 341

Open NSS is well established in T1a tumours and is becoming increasingly accepted in T1b tumours. In the last few years, a tendency to apply a laparoscopic approach for T1a renal tumours has been observed. In some centres this is already the standard of care. Indeed, in experienced hands, the laparoscopic approach achieves intermediate-term oncological and

In a multicenter study (Porpiglia et al., 2010), 63 patients underwent a laparoscopic partial nephrectomy by enucleo-resection with intraoperative ultrasound. The conversion rate was 7.3%: always for bleeding but without requiring RN. Postoperative complication rate was 26%: acute hemorrhage, urinary fistula, fever, chyluria and retroperitoneal hematoma. Acute hemorrhage was the most frequent (9.7%). Half of them were treated with embolization, the other half with reoperation. One patient required a RN. Urinary fistulas (4.4%) required a double J placement and one patient necessitated a re-operation. 6.5% of patients had PSM. There was no correlation between PSM status and tumour size or

**3.2.3.1 Impact of tumour size on peri-operative and post-operative complications** 

Porpiglia (Porpiglia et al., 2010) reviewed 100 consecutive laparoscopic partial nephrectomies. A third of these procedures concerned tumours larger than 4 cm. Intraoperatively, the latter required more often a transperitoneal approach and pelvicalyceal repair. Also, warm ischemia time was longer and they were associated with greater blood loss, however no significant bleeding or conversion occurred. Complication rates were similar in the small versus large tumour groups respectively: fever (6% vs. 3%), acute hemorrhage (4.5% vs. 15.1%, p=0.06), retroperitoneal hematoma (1.5% vs. 6%). One case of pneumonia was seen in the small tumour

Fig. 8. Tumor bed after hemostatic sealant application.

**3.2.2 Complications: Open versus Laparoscopy** 

renal function outcomes comparable to open surgery.

group and one urinary fistula in large tumours group.

location.

**3.2.3 Impact of tumour size** 

Fig. 6. Laparoscopic running suture.

Likewise, the use of haemostatic sealant had no significant impact on warm ischemia time (Porpiglia et al., 2010).

Fig. 7. Hemostatic sealant application.

Likewise, the use of haemostatic sealant had no significant impact on warm ischemia time

Fig. 6. Laparoscopic running suture.

Fig. 7. Hemostatic sealant application.

(Porpiglia et al., 2010).

Fig. 8. Tumor bed after hemostatic sealant application.
