ROBOT-ASSISTED PARTIAL NEPHRECTOMY

Abbreviation

(O)(RA)(L)PN

(open) (robot-assisted) (laparoscopic) partial nephrectomy.

INTRODUCTION

Open partial nephrectomy (OPN) is the standard of care for managing small renal lesions but minimally invasive approaches are gaining increasing acceptance. Laparoscopic PN (LPN) is an advanced surgical procedure and remains a developing standard even in the hands of experts. With careful patient selection and meticulous technique replicating the principles of OPN, it can yield equivalent oncological and renal functional outcomes. Complications of LPN are higher for corticomedullar as opposed to purely cortical tumours, and include bleeding, haematomas and urine leakage [1]. Robotic assistance has been introduced in an attempt to reduce the complexity of LPN.

Gettman et al.[2] published the first report of robot-assisted LPN (RALPN) in 2004. Thirteen procedures were performed, 11 via the transperitoneal approach for anterior/lateral tumours and two via the retroperitoneal approach for posterior tumours. Five patients had standard clamping of the renal artery. A transarterial catheter via groin access was used in the last eight cases to provide iced saline. Three upper pole, five middle and five lower pole lesions were removed. There were no intraoperative complications and there was one instance of postoperative ileus. RCC was found in 10 cases and in one case a positive margin was identified resulting in nephrectomy, which did not show any residual tumour.

The next series was reported by Phillips et al.[3] from New York in 2005. This group also published another report comparing their series of 10 RALPN with 10 cases of LPN performed by the same surgeons [4]. In both these articles, standard laparoscopy was used to mobilize the kidney, isolate the hilum and expose the tumour capsule before docking the robot. There were no statistically significant differences in operative duration, ischaemic time, blood loss, hospital stay, change in creatinine and change in haematocrit between the groups. The authors concluded that although RALPN is feasible they could not find any clinical advantage to its use.

A recent series of RALPN, published in 2007 [5] comes from Detroit, a centre where >3000 robot-assisted laparoscopic prostatectomies have been performed. By contrast to the other two reports, the camera port was placed laterally, which the authors felt prevented the need for extensive colonic mobilization, in addition to better views of the hilum. Also, lateral camera placement prevented collisions of the robotic arms. Of the 10 cases, eight proved to be RCC, one was an oncocytoma and one a lipoma. There have been no recurrences at a mean follow-up of 15 months. Comparative data is presented in Table 1[2,3,5,6].

Table 1.  Summary of RALPN

Variable	Reference
	Gettman et al.[2]	Phillips et al.[3]	Kaul et al.[5]	Rogers et al.[6]
No. of tumours/no. of patients	13/13	12/12	10/10	14/8
Mean (range)
Tumour size, cm	3.5 (2–6)	1.8	2.3 (1–3.5)	3.6 (2.6–6.4)
Operative duration, min	215 (130–262)	265	171 (120–185)	192 (165–214)
Blood loss, mL	170 (50–300)	240	92 (50–150)	230 (100–450)
Warm ischaemia time, min	22 (15–29)	26	21 (18–27)	31 (24–45)
Location, n
Upper pole	3		3
Mid-pole	5		5
Lower pole	5		2
Approach, n
Trans/retroperitoneal	11/2	12/0	10/0	8/0
Conversions, n
To open	0	1	0	0
To laparoscopic		2

Currently there are no controlled studies comparing RALPN with LPN and OPN. In a comparative study between LPN and OPN in their institute, Gill et al.[7] reported longer warm ischaemia times in the LPN group (28 vs 18 min). They also reported decreased complication rates with the use of a gelatin matrix-thrombin sealant (FloSeal) [8]. In an effort to reduce warm ischaemia time, the technical modification of ‘on-demand hilar clamping’ has been described [9], but the pressure seems to stem from achieving tumour resection that is free of positive margin, adequate haemostasis and avoiding urinary leaks. These are the areas in which the features of robot-assisted surgery may prove advantageous. The wristed monopolar hook or the endoshears afford resection in the desired plane irrespective of tumour location. The magnified stereoscopic vision and endowrists can allow precise suturing of bleeding vessels and breached collecting system. However, it is important to note that whilst LPN can be performed by an experienced surgeon with the help of a junior assistant, RALPN in addition to the console surgeon requires the presence of an experienced laparoscopic surgeon at the patient side for hilar clamping and release. This not only takes a degree of surgical control away from the operating surgeon but can prove to be cost-ineffective.

The initial three series of RALPN have clearly dealt with tumours at various locations except central or hilar tumours. Rogers et al.[6] have addressed this in their report on RALPN on 14 tumours in eight patients. There were no positive margins in this series. This is the first report of RALPN in hereditary renal cancer and multiple tumours. Despite the difficult location, and multiple tumours in two patients, the results in this difficult cohort are comparable with the other reports of LPN.

RALPN is clearly feasible, but does have cost implications. This may be offset by bringing the procedure into the repertoire of relatively laparoscopy naïve surgeons. Whilst OPN remains the gold standard for the management of small renal tumours, LPN and RALPN continue to develop.

ACKNOWLEDGEMENTS

Guys and St. Thomas Charity, British Urological Foundation.

CONFLICT OF INTEREST

None declared.